PANAMIC-PACIFIC PELECYPODA 239 



Family GALEOMMATIDAE 

 Shell small, oblong-ovate, often scalelike, usually with an open gap 

 along the ventral margins and in the genus Ephippodonta, the valves are 

 fully open and spread apart so that they lie flat in the same plane. Surface 

 smooth, glossy or covered with small, fine, radial riblets and concentrics, 

 sometimes minutely punctate, the periostracum if preserved, thin. Hinge 

 edentulous or provided with small, weak cardinal teeth and sometimes 

 laterals. The ligament is mostly internal, the resilium being attached to a 

 small pit or groove. The ventral margin is entire or it may be deeply in- 

 dented by a median sinus and a sulcus extending upwards towards the beak, 

 the margin of the valve smooth or crenulate. The mantle extends over the 

 external surface of the valves. Some species are said to be able to move 

 freely about in the manner of snails. 



Genus SOLECAEDIA Conrad, 1849 

 (Scintilla Deshayes, 1855, type species S, Cumingi Desh., selected by 

 Woodward, 1856). 



Type species by monotypy, S. eburnea Conrad. Lower California. 



Shell partly covered by the mantle, the valves subovate, boat-shaped, 

 generally with wide, submedian umbones and rounded, subequal ends, moder- 

 ately convex, white. The surface in fresh shells is covered with a granular, 

 calcareous coating which may become polished and minutely punctate on 

 wear. Hinge plate narrow, bearing two diverging lamellar teeth on each side 

 of a large, socket-like pit occupied in part by the ligament, the margins of 

 the plate beyond the cardinal lamellae grooved. Ligament divided, the 

 tensilium external, small, amphidectic, its longer section posterior of the 

 beak; the resilium internal, and attached to a narrow, linear scar in the roof 

 of the central pit. The pallial line is placed close to the ventral margin, 

 entire. Adductor scars, small, subequal, and lie within and separated from 

 the pallial line. 



Solecardla ebumea Conrad Plate 36, figures 1, la 



Solecardia eburnea Conrad, 1849, Proc. Acad. Nat. Sci. Philadelphia, vol. 4, p. 155. — 

 Conrad, 1850, Jour. Acad. Nat. Sci. Philadelphia, 2d ser., vol. 1, p. 278, pi. 39, 

 fig. 1.— Dall, 1899, Proc. U. S. Nat. Museum, vol. 21, No. 1177, pp. 875, 879, 

 884.— Pilsbry and Lowe, 1932, Proc. Acad. Nat. Sci. Philadelphia, vol. 84, p. 

 136. Hertlein and Strong, 1947, Zoologica, vol. 31, pt. 4, pp. 136, 137. (Not 

 Scintilla eburnea Morch, 1876, renamed by Dall, 1899, as S. morchi). 



Scintilla cumingii Deshayes, 1855, Proc. Zool. Soc. London, p. 173. "Hab. ad littora 

 Panamensis". — Sowerby, 1866, Thes. Conch., vol. 3, pt. 21, Scintilla, p. 177, No. 

 20, pi. 235, figs. 36, 38.— Sowerby, 1875, Conch. Icon., vol. 19, Scintilla, pi. 1, 

 figs. 3a, 3b "Panama". 



Shell relatively large (length nearly 30 mm.), oblong-elliptical or boat- 

 shaped, white. Surface almost smooth except for minute punctations and 

 large, subobsolete radial riblets near the basal margin which is weakly 

 crenulated by them. 



Length 29.2 mm., height 19.2 mm., semidiameter 6.7 mm. Holotype, 

 ANSP 52615. 



Range — Lower California to Panama. Mexico: La Paz. (Pilsbry and 

 Lowe). Nicaragua: San Juan del Sur (Pilsbry and Lowe). Panama: Panama 

 (Cuming and Deshayes). 



