Cerodrillia clappi Bartsch & Rehder, 1939

Fallon, Phillip J., 2016, Taxonomic review of tropical western Atlantic shallow water Drilliidae (Mollusca: Gastropoda: Conoidea) including descriptions of 100 new species, Zootaxa 4090 (1), pp. 1-363: 64-66

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http://doi.org/10.11646/zootaxa.4090.1.1

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scientific name

Cerodrillia clappi Bartsch & Rehder, 1939
status

 

Cerodrillia clappi Bartsch & Rehder, 1939 

( Plate 25View PLATE 25)

Cerodrillia clappi Bartsch & Rehder, 1939: 128  , pl. 17, fig. 4. Powell (1966: 73, pl. 11, fig. 6); Abbott (1974: 271, sp. 3022 a [as a probable variant of C. perryae  ]); Kaicher (1984: card 3931); Turgeon et al. (1988: 96); Lyons (1998: 27); Turgeon et al. (1998: 102); Williams (2005; 2009: 1521, left photo only [of holotype]).

Not this species or unconfirmed extralimital reports.

Cerodrillia (Cerodrillia) clappi (Bartsch & Rehder, 1939)  : Perry (1940: 164, pl. 38, fig. 260 [fig. not of C. clappi  = Cerodrillia sanibelensis  , new species]).

Cerodrillia clappi Bartsch & Rehder, 1939  : Perry & Schwengel (1955: 181, pl. 38, fig. 260 [fig. not of C. clappi  = C. sanibelensis  ]); Morris (1973: 247, pl. 68, fig. 9 [= C. sanibelensis  ]); Odé (1991: 25 [description not of C. clappi  , prob. = Douglassia bealiana Schwengel & McGinty, 1942  ]); Abbott & Morris (1995: 256 [description = C. sanibelensis  ]); Absalão et al. (2005: 22, fig. 4 [ Brazil; fig. not of C. clappi  ]); Williams (2009: 1521 [left photo of right pair = C. sanibelensis  ]).

Cerodrillia cf. clappi Bartsch & Rehder, 1939  : Tunnell et al. (2010: 242 [photo not of C. clappi  prob. = D. bealiana  ]).

Type material. Holotype 11.6 x 4.2 mm (USNM 493408). Eleven paratypes are known. Bartsch & Rehder stated that “the type USNM no. 493408 is one of a series of specimens dredged by J.B. Henderson, Jr. at 4 fathoms in Hawk Channel, Fla.” but did not give the lot numbers. Two lots were found that have data labels matching this locality and are presumed be part of the “series of specimens” and thus part of the type series: 2 spec., 9.4 x 3.5 & 7.9 x 3.2 mm, in 3–20 ft [1–6 m], Eolis Sta.  65, Hawk Channel, Key West, Florida Keys, J.B. Henderson! 15 May 1913 (USNM 411108), and 7 spec., the best 5: 9.8 x 3.9, 7.7 x 3.2, 9.8 x 3.7, 8.5 x 3.4 & 10.7 x 4.0 mm, in 7 m, Hawk Channel, Florida Keys, J.B. Henderson coll. (USNM 411270). This additional lot of paratypes was identified in the same paper: 2 spec., 8.5 x 3.6 & 8.1 x 3.3 mm, from No Name Key, Florida Keys, ex. H. Hemphill coll. (USNM 27653).

Type locality. R/V Eolis, Hawk Channel  , [Key West], Florida Keys, in 4 fms [7 m] depth. Although not explicitly stated by Bartsch & Rehder but on the basis of Eolis  log data (Bieler & Mikkelsen, 2003) the type was probably collected at Eolis Stations  65 or 66, which was sampled in Hawk Channel off Key West on 15 or 16 May 1913. This is corroborated by the data label in lot USNM 411108 (part of the Henderson material examined by Bartsch & Rehder and from which the type was selected), that explicitly gives the location as Eolis  Station 65. The data label of the other lot believed to be part of the original material, USNM 411270, does not give the station number.

Other material examined. An additional 8 specimens were examined that are believed to be this species: 3 spec., 10.4 x 4.3, 8.9 x 3.3 & 8.1 x 3.2 mm, in 1 m, NE of No Name Key, Florida Keys, D. Steger! 1 Aug 1959 (UF 158170); 2 spec., 10.1 x 4.2 & 8.7 x 3.5 mm, W of John Sawyer Bank [about 5 km NW of Fanny Keys, Marathon], J. Moore! Nov 1966 (EFG 11608); 1 spec., 10.4 x 3.8 mm, in 61 m, Marathon Key, 1978 (USNM 900102); 2 spec., 11.5 x 4.5 & 13.1 x 4.8 mm, in 27–30 m, W of Anclote Key, Pasco Co., W Florida, J. Moore! (ANSP 314402).

Range and habitat. Florida Keys; W Florida (Pasco Co.). Reported from 1– 61 m.

Description. Shell small (to 13.1 mm), somewhat narrowly fusiform for genus, anterior produced, small (to 11.6 mm); whorls flat-to slightly convex, sutures appressed, number to 8 ½, last whorl about 60 % of total length. Protoconch of 1 ½– 1 ¾ smooth round whorls. Axial sculpture of moderately broad, low opisthocline ribs that run from suture-to-suture on spire whorls, evanescent on shell base, round in axial profile on spire whorls, more angular on last whorl, rib crests round; ribs number 8–10 on the penultimate and 6–9 on the last whorl to the varix, their interspaces wider than the ribs. Growth striae microscopic. Vari x cup handle-like, just behind the anal sinus. Spiral sculpture of fine threads on the shell base, becoming stronger and ridge-like anteriorly; about 3 on the shell base. Sulcus not distinct but shoulder region marked by lower, narrower recurved ribs, reflecting the outline of the anal sinus. Outer lip thin, with a deep anal sinus posteriorly, and a slight stromboid notch anteriorly; edge of lip forms a low, flattened arc from the anal sinus to the stromboid notch. One axial fold may be present. Anal sinus Ushaped, just below the suture on whorl shoulder, sides slightly divergent, entrance offset by a parietal lobe. Inner lip recumbent but pinched along the anterior canal, margined; formed into a parietal lobe posteriorly. Anterior canal short but distinct, open, with a slight hook to the left at its tip viewed ventrally, unnotched; anterior fasciole with about 5 spiral ridges; fasciole not swollen. Color off-white to light brown, shell base and ribs lighter, usually white. The holotype has a narrow light-brown peripheral band, which is not present in most other specimens examined.

Remarks. Nomenclature. Cerodrillia clappi  is the type of the genus. Confusion regarding the true nature of this species began early with the publication of a guide book (Perry 1940) with the illustration of a different species labeled as C. clappi  . Figure 260 in Perry (1940), and also in Perry & Schwengel (1955), do not match the type of C. clappi  , as captioned, but is a different species, which is described below as Cerodrillia sanibelensis  , new species. Ambiguity about the species continued, Abbott (1974: 271) considered C. clappi  a probable variant of C. perryae  , and Abbott & Morris (1995: 256) called it a form of Cerodrillia thea (Dall, 1884)  . A comparison of shell morphology with other Cerodrillia  supports separation of C. clappi  as discrete species. The confusion continued with the identification of Texas material as C. clappi (Odé, 1991: 25)  but he noted that much of the material in the 16 lots of the Houston Museum of Natural Science (HMNS) survey better resembled C. perryae  figured by Perry & Schwengel (1955: pl. 38, fig. 260 A), rather than their figure of C. clappi  ( C. perryae  was not described as having a mid-whorl stripe; C. clappi  was). Tunnell et al. (2010: 240) changed the identification of the Texas species to Cerodrillia cf. clappi  . The Texas material is neither C. clappi  nor C. perryae  , but rather Douglassia bealiana Schwengel & McGinty, 1942  on the basis of Odé’s description and the figure in Tunnell et al. Variability. The average length of 18 specimens is 9.62 mm (7.7–13.1 mm), and their average W/ L ratio  is 0.392. Bartsch & Rehder include in their description of the species the dark spiral stripe seen in the holotype; however, specimens appear to be variable for this character. Specimens from off Anclote Key, Pasco Co. and deeper water differ somewhat from the Florida Keys specimens from shallower water (27–30 m versus 1–7 m) have somewhat fewer ribs on penultimate whorl (8 versus 8–10) are believed to only represent a regional variation. Curiously, these deeper water specimens all have the faint spiral stripe that is present on the holotype but absent on specimens of the remaining type series. Identification. Cerodrillia clappi  differs from C. perryae  in color, usually off white to light brown with a white base, without a brown band. It differs from C. sanibelensis  , new species, in being more slender and having more ribs. Specimens from Pasco Co. differ from C. harryleei  , new species in possessing more streamlined, not knob-like ribs and are a different color.