Periploma skoglundae Valentich-Scott & Coan

Valentich-Scott, Paul & Coan, Eugene V., 2010, Three new species of Periploma (Bivalvia, Periplomatidae) from the Panamic Province, Zootaxa 2673, pp. 65-68 : 65-66

Periploma skoglundae Valentich-Scott & Coan , new species

Figures 1 A–G

Periploma margaritaceum (Lamarck) , auctt., non Corbula margaritacea Lamarck, 1801: 137 ; P. margaritaceum Lamarck : Bernard, 1989: 3 –4; P. margaritaceum Lamarck : Skoglund, 1991: 53.

Description. Shell ovate-elongate; right valve much more inflated than left; left valve fitting well inside right valve; anterior end broadly to sharply rounded; inequilateral, anterior end much longer; posterior end truncate, with broad, deep radial sulcus, more prominent in right valve; sculpture of fine commarginally arranged granules, densely pustulose posterior to sulcus; pallial sinus moderately wide and deep, extending past beaks; chondrophore moderately small, narrow, anteriorly directed; lithodesma small, narrow, just anterior of chondrophore. Length to 12 mm [SBMNH].

Type material. SBMNH 83429, holotype, paired valves; length, 11 mm; height, 7 mm; paratypes, SBMNH 14601, 1 pair valves from holotype lot; SBMNH 149603, 3 paired valves, 9 single valves from type locality. Additional paratypes from Caleta de los Angeles, Jalisco, Mexico; 19°18'11"N, 104°49'52"W; 6–20 m: SBMNH 149602, 3 paired valves, 22 single valves; UNSM 1146206, 1 paired valves, 2 single valves; CAS 184227, 1 paired valves, 2 valves; LACM 3136, 1 paired valves, 2 single valves.

Type locality. Bahía Chamela, Jalisco, Mexico; 19°33’N, 105°07’W; 12–18 m; mud.

Etymology. Named in honor of Carol Skoglund of Phoenix, Arizona, who has continually advanced our understanding of the Panamic Mollusca for the past four decades.

Distribution. Punta Raza, Nayarit (21.0°N) [SBMNH], to Bahía Cuastecomate, Jalisco (19.2°N) [SBMNH], Mexico; 2–33 m [SBMNH], mud.

Comparisons. Initially reported by Bernard (1989) from the eastern Pacific as the western Atlantic type species of the genus, P. margaritacea ( Lamarck, 1801) ( Figures 1 H–I), this new species differs from it in having a prominent posterior radial sulcus, a wider, deeper pallial sinus, and lacking an escutcheon. The western Atlantic species is well figured in Mikkelsen & Bieler (2007: 196).

Literature. F. R. Bernard (1989, 3–4, as P. margaritaceum ), Skoglund (1991, as P. margaritaceum ).

Figures

FIGURE 1. A – G. Periploma skoglundae new species; A – C, E – F, holotype (SBMNH 83429) length = 11 mm. A. Exterior of left valve. B. Interior of left valve. C. Exterior of right valve. D. Dorsal view of both valves joined (paratype SBMNH 149601). E. Hinge of right valve. F. Hinge of left valve. G. Interior of right valve. H – I. Periploma margaritacea (Lamarck, 1801) original illustration from Bruguière (1797: pl. 230, fig. 6 a, b), length = 28 mm. H. Interior of right valve. I. Exterior of right valve. J – O. Periploma kaiserae new species, holotype (SBMNH 149599) length = 15 mm. J. Exterior of left valve. K. Interior of left valve. L. Exterior of right valve. M. Interior of right valve. N. Hinge of right valve. O. Hinge of left valve. P – R. Periploma planiscula Sowerby, 1834, syntype (BMNH 1927.3.4.353) length = 42 mm. P. Exterior of left valve. Q. Interior of left valve. R. Interior of right valve.