Littorininae, Children, 1834

Reid, David G., 2009, The genus Echinolittorina Habe, 1956 (Gastropoda: Littorinidae) in the western Atlantic Ocean 2184, Zootaxa 2184 (1), pp. 1-103 : 12-13

Key to the Littorininae of the tropical and subtropical western Atlantic

Although the genus Echinolittorina is a well-defined monophyletic group in molecular phylogenetic analyses, there are no known morphological synapomorphies. Shells are convergent with those of several other littorinid genera. To minimize confusion, the following key includes all 17 littorinine species that have been recorded from the tropical and subtropical western Atlantic region, belonging to the genera Echinolittorina , Tectarius , Littoraria and Cenchritis . Discrimination is based primarily on easily observable characters of the shell, with the addition of diagnostic characters of the penis and pallial oviduct. References to figures of shells and penes of all species are given, together with information on distribution and habitat.

1 Nodulose or granulose .................................................................................................................................................. 2

- Spiral ribs or grooves, or smooth .................................................................................................................................. 5

2 Grey to white; white aperture; 15–30 mm; 4 rows of granules on spire whorls; paucispiral operculum (opercular ratio OR 0.61–0.65); penis without glands ( Reid 1989: fig. 6m); multispiral pallial oviduct. Bermuda, Bahamas, Florida, Caribbean. Wood and rocks ......................................... Cenchritis muricatus ( Linnaeus, 1758) ( Bequaert 1943: pl. 1)

- Grey brown; brown aperture with basal white band; nodulose sculpture..................................................................... 3

3 12–20 mm; 2 rows of pointed tubercles on last whorl; multispiral operculum (OR 0.78–0.81); penis with 3–4 mamilliform penial glands ( Reid 1989: fig. 7a). Bahamas, Florida, Greater Antilles. Rocks ....................................... .............................................. Tectarius (Tectininus) antonii ( Philippi, 1846 b) ( Bandel & Kadolsky 1982: figs 56–59)

- 6–23 mm; 2–4 rows of rounded or pointed nodules on last whorl; paucispiral operculum (OR 0.53–0.66) .............. 4

4 2–3 rows of rounded or pointed nodules on last whorl; OR = 0.60–0.66. Bermuda, Bahamas, Florida, Caribbean. Rocks .................................................................................................................................. E. tuberculata ( Figs 31 , 32 )

- 4 rows of rounded, white nodules on black shell; OR = 0.53–0.64. Oceanic islands off Brazil. Rocks ........................ .................................................................................................................................................. E. vermeiji ( Figs 35 , 36 )

5 Small, 3–9 mm; smooth with single incised line at periphery; narrow or wide pseudumbilicus; penis lacking glands ....................................................................................................................................................................................... 6

- Large,> 10 mm; spiral ribs or grooves; no pseudumbilicus; penis with glands........................................................... 7

6 High-turbinate; brown with white spots or lines; deep pseudumbilicus. Bermuda, Bahamas, Florida, Gulf of Mexico, Caribbean. Rocks, algae ............................................................................................................ E. meleagris ( Figs 3 , 4 )

- Globular; brown, or white with black dots; narrow pseudumbilicus. Bermuda, Bahamas, Florida, Caribbean. Rocks, algae ......................................................................................................................................... E. mespillum ( Figs 7 , 8 )

7 Aperture cream, yellow or with external pattern showing through; penis without mamilliform penial glands; multispiral pallial oviduct or ovoviviparous. Rocks, grass, wood and mangroves ..................................... Littoraria 8

- Aperture brown with white band at base and sometimes at shoulder; penis with single mamilliform penial gland and glandular disc. Rocks ................................................................................................................................................. 12

8 ≥ 30 fine grooves on last whorl..................................................................................................................................... 9

- ≤ 26 strong grooves on last whorl ............................................................................................................................... 10

9 To 40 mm; 30–45 grooves on last whorl; cream with or without brown lines and dashes; columella wide, flat, white to lilac and stained brown; penis bifurcate, small filament ( Reid 1986: fig. 4f). Gulf of Mexico, Florida, Caribbean, to French Guyana. Driftwood, mangroves, sheltered rocks ........................................................................................... ........................................................................... Littoraria nebulosa ( Lamarck, 1822) ( Bequaert 1943: pl. 4, figs 1–4)

- To 24 mm; 48–75 grooves on last whorl; thin-shelled; colour polymorphic; columella narrow, excavated, brown to purple; penis bifurcate, large filament ( Reid 1986: fig. 4o); ovoviviparous (embryos in mantle cavity). Bermuda, Florida, Gulf of Mexico, Bahamas, Caribbean, to Brazil. Mangroves, sheltered rocks ................................................ ...................................................................................... Littoraria angulifera ( Lamarck, 1822) ( Reid 1986: fig. 99d–f)

10 Fine, chocolate brown tessellation or oblique lines; 23–25 grooves on last whorl; columella wide, flat, lilac to purple brown; penis bifurcate, vermiform filament, closed sperm duct ( Reid 1986: fig. 4h). Bahamas, Florida, Caribbean. Driftwood, mangroves, sheltered rocks .......... Littoraria tessellata (Philippi, 1847) ( Bequaert 1943: pl. 4, figs 8–10)

- Cream, with or without brown dots ............................................................................................................................ 11

11 To 20 mm; 16–26 grooves on last whorl; columella thick, excavated, brown; penis not bifurcate, vermiform filament, closed sperm duct ( Reid 1986: fig. 4i). Caribbean to Brazil. Mangroves, rocks ............................................ .................................................................... Littoraria flava ( King & Broderip, 1832) ( Bequaert 1943: pl. 4, figs 5–7)

- To 30 mm; 20–22 strong grooves on last whorl; thick shell; columella thick, not excavated, orange brown; penis not bifurcate, open sperm groove ( Reid 1986: fig. 4m). New Jersey to NE Florida, N Gulf of Mexico. Salt marshes ...... .................................................................................................... Littoraria irrorata ( Say, 1822) ( Bequaert 1943: pl. 2)

12 To 29 mm; high turbinate, rounded periphery; 8–10 primary grooves on spire whorls; 40–60 fine grooves on last whorl; white, with or without dark axial lines; penis with very large mamilliform penial gland filling the wrinkled base. Bermuda, Bahamas, Florida, Caribbean ........................................................................... E. ziczac ( Figs 14 , 15 )

- <20 mm; slightly to strongly angled periphery; 6–10 primary grooves on spire whorls; <35 grooves on last whorl; black-and-white pattern; penis with small mamilliform penial gland on branch of base .......................................... 13

13 Wide grooves on last whorl (0.5–1 times rib width); 6–8 primary grooves on spire whorls; penis with obliquely wedge-shaped tip and subterminal opening of sperm groove. Bermuda, Bahamas, Florida, Gulf of Mexico, Caribbean ........................................................................................................................... E. jamaicensis ( Figs 18 , 19 )

- Incised or faint lines; 6–10 primary grooves on spire whorls; penis with terminal opening of sperm groove........... 14

14 Tall; flat-sided spire; sharp peripheral keel; 6–7 primary grooves on spire whorls; OR 0.52–0.57. Bermuda, Bahamas, Florida, Caribbean ................................................................................................ E. angustior ( Figs 27 , 28 )

- Slightly rounded whorls; slightly angled periphery; 7–10 primary grooves on spire whorls; OR 0.34–0.54 ............ 15

15 9–10 primary grooves on spire whorls; OR 0.45–0.54; penis with swollen pointed filament. Brazil, Uruguay............ ................................................................................................................................................. E. lineolata ( Figs 10 , 11 )

- 7–10 primary grooves on spire whorls; OR 0.34–0.44; penis with glandular thickening at base of filament only ... 16

16 Whorls slightly rounded; 8–10 primary grooves on spire whorls; spiral black band on spire and usually last whorl. Caribbean Sea, on continental shores of mainland and high islands ................................... E. interrupta ( Figs 22 , 23 )

- Whorls rounded; 7–8 primary grooves on spire whorls; spiral black band on spire but absent on last two whorls. Gulf of Mexico, Florida to N Carolina, tolerates sheltered and turbid conditions ....... E. placida new species ( Figs 25 , 26 )

Figures

FIGURE 3. Echinolittorina meleagris. A, B, Arnos Vale Bay, Tobago (BMNH 20080956). C, South Water Cay, Belize (BMNH 20080957). D, Sebastian Inlet, Brevard Co., Florida, USA (BMNH 20080958). E–H, Lucea Bay, Jamaica (BMNH 20080959). I, Eight-mile Rock, Grand Bahama I., Bahamas (BMNH 20080960). J, St Thomas (BMNH 1856.7.23.14). K, M, St Vincent (BMNH 20080961). L, Phasianella meleagris Beck in Potiez & Michaud, 1838, neotype, St Vincent (BMNH 20080962). N, Cienfuegos, Cuba (BMNH 20080963). O, Virgin Gorda, British Virgin Is (BMNH 20080964).

FIGURE 4. Echinolittorina meleagris. A–G, penes. H, head. I, J, pallial oviducts. K–M, egg capsules. N–P, paraspermatozoa. A–C, H, K–P, Sebastian Inlet, Brevard Co., Florida, USA (BMNH 20080958; shell H A = 5.3 mm, B = 4.4 mm, C = 5.4 mm, H = 4.4 mm). D, E, Lucea Bay, Jamaica (BMNH 20080959; shell H D = 4.3 mm, E = 3.7 mm). F, J, Tulum, Quintana Roo, Mexico (BMNH 20080965; shell H F = 5.1 mm, J = 6.4 mm). G, Burt Point, Readtown, Tortola, British Virgin Islands (ANSP A7222; shell H = 4.0 mm). I, Colon I., Bocas del Toro, Panama (BMNH 20080966; shell H = 5.0 mm). Shading conventions as in Figure 15.

FIGURE 7. Echinolittorina mespillum. A, Helix mespillum Mühlfeld, 1824, neotype, Cienfuegos, Cuba (BMNH 20080967). B, Cienfuegos, Cuba (BMNH 20080968). C, Eight-mile Rock, Grand Bahama I., Bahamas (BMNH 20080969). D, Black Bat Cave, Nassau, Bahamas (BMNH 20080970). E, Jamaica (BMNH 20080971). F, G, S Bimini, Bahamas (BMNH 20080972). H, Morant Reef, Jamaica (BMNH 20080973).

FIGURE 8. Echinolittorina mespillum. A, head and penis. B–F, penes. G, egg capsule (after D’Asaro 1986). H–J, pallial oviducts. K, L, paraspermatozoa. A, C, H, I, Priory, Jamaica (BMNH 20080974; shell H A = 3.9 mm, C = 3.5 mm, H = 4.7 mm, I = 5.1 mm). B, D, Morant Reef, Jamaica (BMNH 20080973; shell H B = 5.3 mm. D = 5.7 mm). E, Boca Raton Inlet, Palm Beach Co., Florida, USA (ANSP A8181b). F, J–L, Eight-mile Rock, Grand Bahama I., Bahamas (BMNH 20080969; shell H F = 5.8 mm, J = 5.9 mm). G, South Bimini, Bahamas. Shading conventions as in Figure 15.

FIGURE 10. Echinolittorina lineolata. A, Littorina lineolata d’Orbigny, 1840, lectotype, Rio de Janeiro, Brazil (BMNH 1854.12.4.363/1). B, Bara Cunha, 60 km S Natal, Rio Grande do Norte, Brazil (BMNH 20080975). C, E, Curumirin, Rio de Janeiro state, Brazil (MZSP 31267). D, Araruama Point, Cabo Frio, Rio de Janeiro state, Brazil (BMNH 20080976). F, Pernambuco, Brazil (BMNH 1844.8.7.1). G, Pernambuco, Brazil (BMNH 1924.12.3.10). H, Natal, Brazil (BMNH 20080977). I, I. Queimada Grande, São Paulo state, Brazil (MZSP 24919). J, Cabo Polonia, Uruguay (USNM 359202). K, Barra, Rio Grande, Brazil (BMNH 1958.4.10.2). L, I. Sta Barbara, Abrolhos Arch., Brazil (USNM 770002).

FIGURE 11. Echinolittorina lineolata. A–E, penes; E abnormal, with two mamilliform penial glands. F, head and penis. G, pallial oviduct. H, egg capsule (after E. Marcus & E. du B. Marcus 1963). I–K, paraspermatozoa. A, B, Santa Catarina, Brazil (USNM 264059; shell H A = 6.5 mm, B = 6.4 mm). C, Cigarras Beach, São Sebastião, São Paulo state, Brazil (BMNH 20080979; shell H = 7.2 mm). D, I, Araruama Point, Cabo Frio, Rio de Janeiro state, Brazil (BMNH 20080976; shell H = 6.7 mm). E, J, K, Natal, Brazil (BMNH 20080978; shell H E = 7.2 mm). F, Natal, Brazil (BMNH 20080977; shell H = 4.0 mm). G,Ilha de Queimada Grande, São Paulo state, Brazil (MZSP 24919; shell H = 12.9 mm). H, São Paulo state, Brazil. Shading conventions as in Figure 15.

FIGURE 14. Echinolittorina ziczac. A, Trochus ziczac Gmelin, 1791, lectotype figure (b), figure 1599 from Chemnitz (1781), West Indies. B, H, Nenton Point, Nelson’s Dockyard, Antigua (BMNH 20080980). C, Eight-mile Rock, Grand Bahama I., Bahamas (BMNH 20080981). D, G, Rocky Bay, Devonshire, Bermuda (BMNH 20080982). E, F, I, Little Stirrup Cay, Berry Is, Bahamas (BMNH 20080983).

FIGURE 15. Echinolittorina ziczac. A–E, penes. F, G, two views of pallial oviduct, lateral and ventral (with transverse section). H, head. I, J, egg capsules (I after Bandel 1974; J after Borkowski 1971). K–M, paraspermatozoa. A, Playa Huertas, Portabelo, Panama (BMNH 20080984; shell H = 10.0 mm). B, H, K, M, Fort Pierce Inlet, St Lucie Co., Florida, USA (BMNH 20080985; shell H = 10.6 mm). C, D, L, South Water Cay, Belize (BMNH 20080986; shell H C = 12.4 mm, D = 10.4 mm). E–G, Jingle Beach, Priory, Jamaica (BMNH 20080987; shell H E = 12.3 mm, F, G = 19.2 mm). I, Santa Marta, Colombia. J, south Florida, USA. Abbreviations: ag, albumen gland (sparse stipple); b, copulatory bursa (dashed outline; visible by transparency); eg, egg groove (visible by transparency); mpg, mamilliform penial gland, opening through external papilla; mr, mucus reservoir of mamilliform penial gland (visible by transparency); ocg, opaque capsule gland (mid stipple); pf, smooth penial filament; pgd, penial glandular disc; psg, penial sperm groove on antero-dorsal edge of penis; ro, renal oviduct; seg, subepithelial glandular tissue of mamilliform penial gland (visible by transparency); sg, sperm groove of pallial oviduct; sr, seminal receptacle (heavy stipple); tcg, translucent capsule gland (cross-hatched); wb, wrinkled base of penis.

FIGURE 18. Echinolittorina jamaicensis. A–C, Eight-mile Rock, Grand Bahama I., Bahamas (BMNH 20080988). D, E, St Ann’s Bay, Jamaica (BMNH 20080989). F, Fort Pierce Inlet, St Lucie Co., Florida, USA (BMNH 20080990). G,H, Fort Pierce Inlet, St Lucie Co., Florida, USA (BMNH 20080991). I, Cape Florida, Dade Co., Florida, USA (BMNH 20080992). J, K, Little Stirrup Cay, Berry Is, Bahamas (BMNH 20080993). L, La Habana, Cuba (BMNH 20080994). M, Littorina janaicensis C.B. Adams, 1850, lectotype, Jamaica (MCZ 186133). N, Fort Charlotte, Lucea, Jamaica (BMNH 20080995). O, Sebastian Inlet, Brevard Co., Florida, USA (BMNH 20080996).

FIGURE 19. Echinolittorina jamaicensis. A–E, G, penes. F, head. H, pallial oviduct. I, J, paraspermatozoa. K, egg capsule (after Borkowski 1971). A, D, Eight-mile Rock, Grand Bahama I., Bahamas (BMNH 20080988; shell H A = 10.4 mm, D = 11.2 mm). B, Tulum, Quintana Roo, Mexico (BMNH 20080997; shell H = 12.4 mm). C, F, I, Fort Pierce Inlet, St Lucie Co., Florida, USA (BMNH 20080990; shell H C = 10.5 mm, F = 9.6 mm). E, G, Jingle Beach, Priory, Jamaica (BMNH 20080999; shell H E = 10.9 mm, G = 8.0 mm). H, Fort Pierce Inlet, St Lucie Co., Florida, USA (BMNH 20080998; shell H = 14.0 mm). J, La Toc Beach, St Lucia (BMNH 20081000). K, south Florida. Abbreviation: o, subterminal opening of penial sperm groove. Shading conventions as in Figure 15.

FIGURE 22. Echinolittorina interrupta. A, Litorina ziczac var. interrupta C.B. Adams in Philippi, 1847, neotype, Jamaica (MCZ 186123). B, St Vincent (BMNH 20081001). C, D, Punta Gorda, Belize (BMNH 20081002). E, J, K, Limon Bay, Panama (USNM 734748). F, Scarborough, Tobago (BMNH 20081003). G, Grande Anse Beach, Grenada (BMNH 20081004). H, I, Cahuita, Costa Rica (BMNH 20081005). L, M, Fort Charlotte, Lucea, Jamaica (BMNH).

FIGURE 23. Echinolittorina interrupta. A–G, penes. H, pallial oviduct. I, egg capsule (after Bandel 1974). J–L, paraspermatozoa. A, Cahuita, Costa Rica (BMNH 20081005; shell H = 5.9 mm). B, L, Lucea, Jamaica (BMNH 20081008; shell H = 12.0 mm). C, D, H, Fort Charlotte, Lucea, Jamaica (BMNH 20081006; shell H C = 14.0 mm, D = 14.3 mm, H = 14.9 mm). E, Punta Gorda, Belize (BMNH 20081002; shell H = 9.1 mm). F, J, K, South Water Cay, Belize (BMNH 20081007; shell H = 10.9 mm). G, Senagan I., Trinidad (BMNH 1934.2.13.253; shell H = 10.4 mm). I, Santa Marta, Colombia. Shading conventions as in Figure 15.

FIGURE 25. Echinolittorina placida new species. A, holotype, Marco I., Collier Co., Florida, USA (BMNH 20081009). B, C, paratypes, Marco I., Collier Co., Florida, USA (BMNH 20081010). D, Wrightsville Beach, Wilmington, North Carolina, USA (BMNH 20081011). E, Venice, Sarasota Co., Florida (BMNH 20081012). F, Tolomato R., N of St Augustine Inlet, St Johns Co., Florida (BMNH 20081013). G, H, Lido Key, Florida (BMNH 20081014). I, J, Seybaplaya, Campeche, Mexico (BMNH 20081015). K, English Navy Cove, Sta Rosa Co., Florida (BMNH 20081016). L, M, Dauphin I., Alabama (BMNH 20081017). N, O, Marineland, Flagler Co., Florida (BMNH 20081018). P, Corpus Christi Bay, Texas, USA (BMNH 20081019). Q, Pass-a-Grille, Pinellas Co., Florida (USNM 820422).

FIGURE 26. Echinolittorina placida new species. A–E, G, H, penes. F, head and penis. I, pallial oviduct. J, egg capsule. K–M, paraspermatozoa. A, paratype, Marco I., Collier Co., Florida, USA (BMNH 20081010; shell H = 7.4 mm). B, C, I, Corpus Christi Bay, Texas, USA (BMNH 20081023; shell H B = 9.5 mm, C = 8.9 mm, I = 11.3 mm). D, M, 20 km S Campeche, Mexico (BMNH 20081020; shell H = 8.0 mm). E, H, Seybaplaya, 30 km S Campeche, Mexico (BMNH 20081015; shell H E = 7.2 mm, H = 8.1 mm). F, South Jetty, Port Aransas, Texas, USA (BMNH 20081021; shell H = 2.8 mm). G, Texas City sea dyke, Texas, USA (BMNH 20081021; shell H = 10.1 mm). J, Fort Pierce Inlet, St Lucie Co., Florida, USA (BMNH 20081022). K, Corpus Christi Bay, Texas, USA (BMNH 20081019). L, Wrightsville Beach, North Carolina, USA (BMNH 20081011). Shading conventions as in Figure 15.

FIGURE 27. Echinolittorina angustior. A, Littorina angustior Mörch, 1876, lectotype, La Habana, Cuba (ZMK). B, C, South Water Cay, Belize (BMNH 20081024). D, Littorina carinata d’Orbigny, 1841, lectotype, Cuba (BMNH 1854.10.4.128). E, West Sister Rock, Monroe Co., Florida, USA (BMNH 20081027). F–I, Jingle Beach, Priory, Jamaica (BMNH 20081028). J, Tavernier Key, Monroe Co., Florida, USA (BMNH 20081025). K–M, Fort Pierce Inlet, St Lucie Co., Florida, USA (BMNH 20081026). N, Little Stirrup Cay, Berry Is, Bahamas (BMNH 20081029). O, P, Virgin Gorda, British Virgin Is (BMNH 20081030). Q, R, Antigua (BMNH 20081031). S, Bayahibe, Dominican Republic (BMNH 20081032).

FIGURE 28. Echinolittorina angustior. A–G, penes. H, pallial oviduct. I, J, egg capsules. K–M, paraspermatozoa. A, B, G,I–K,Fort Pierce Inlet, St Lucie Co., Florida, USA (BMNH 20081035; shell H A = 7.7 mm, B = 8.9 mm, G = 8.0 mm). C, D, M, Rocky Bay, Devonshire, Bermuda (BMNH 20081036; shell H C = 10.4 mm, D = 7.1 mm). E, Playa Huertas, Portobelo, Panama (BMNH 20081033; shell H = 11.3 mm). F, L, La Toc Beach, St Lucia (BMNH 20081034; shell H = 8.0 mm). H, Fort Pierce Inlet, St Lucie Co., Florida, USA (BMNH 20081026; shell H = 12.3 mm). Shading conventions as in Figure 15.

FIGURE 31. Echinolittorina tuberculata. A, Litorina tuberculata Menke, 1828, neotype, Pointe des Châteaux, E tip Grande Terre, Guadeloupe (USNM 749822). B, Barbados (BMNH 20081039). C, H, Nenton Point, Antigua (BMNH 20081040). D, N, Tulum, Quintana Roo, Mexico (BMNH 20081041). E, Fort Pierce Inlet, St Lucie Co., Florida, USA (BMNH 20081042). F, I, South Water Cay, Belize (BMNH 20081043). G, Goffs Cay, Belize (BMNH 20081044). J–L, Little Stirrup Cay, Berry Is, Bahamas (BMNH 20081045). M, Bermuda (BMNH 1911.12.21.873). O, Pigeon I., St Lucia (BMNH 20081046). P, Belle Fontaine, Martinique (BMNH 20081047). Q, Bermuda (BMNH 20081048).

FIGURE 32. Echinolittorina tuberculata. A–E, penes. F, pallial oviduct. G, H, egg capsules (G after Borkowski 1971; H, after Bandel 1974). I, head. J–L, paraspermatozoa. A, K, South Water Cay, Belize (BMNH 20081050; shell H = 9.3 mm). B, Playa Giron, S Cuba (BMNH 20081060; shell H = 6.8 mm). C, D, I, L, MacArthur Causeway, Biscayne Bay, Florida, USA (BMNH 20081049; shell H C = 9.5 mm, D = 9.6 mm, I = 9.4 mm). E, F, Antigua (BMNH 20081058; shell H E = 11.9 mm, F = 16.4 mm). G, south Florida, USA. H, Santa Marta, Colombia. J, Jingle Beach, Priory, Jamaica (BMNH 20081061). Shading conventions as in Figure 15.

FIGURE 35. Echinolittorina vermeiji. A, Nodilittorina (Nodilittorina) vermeiji Bandel & Kadolsky, 1982, holotype, Baia de Sueste, Isla Fernando de Noronha, 540 km NE Recife, Brazil (USNM 749819). B, G, Nodilittorina (Nodilittorina) vermeiji Bandel & Kadolsky, 1982, paratypes, Fernando Noronha, Brazil (BMNH 1889.2.21.63, 1887.2.9.1831). C, E, F, H, Ensenada dos Portugueses, Ilha da Trindade, Brazil (BMNH 1989066). D, Ponta de Santo Antonio, Fernando Noronha, Brazil (BMNH 20081063). I, Ilha da Trindade, Brazil (BMNH 1906.11.1.11). J, K, Ilha do Cemiterio, Atol das Rocas, Brazil (BMNH 1989064). L–N, Buraco da Raquel, Fernando Noronha, Brazil (MZSP 31398).

FIGURE 36. Echinolittorina vermeiji. A–F, penes. G, pallial oviduct. A, B, Porto, Fernando de Noronha, Brazil (MZUSP 31636; shell H A = 6.7 mm, B = 5.7 mm). C, D, Buraco da Raquel, Fernando de Noronha, Brazil (MZSP 31398; shell H C = 12.7 mm, D = 20.1 mm). E–G, Ensenada dos Portugueses, Ilha da Trindade, Brazil (BMNH 1989067; shell H E = 7.6 mm, F = 8.0 mm, G = 8.5 mm). Shading conventions as in Figure 15.