PANAMIC-PACIFIC PELECYPODA 231 



Family KELLIIDAE 

 Shell small, ovate or orbicular, thin, convex, white or subtranslucent, 

 the umbones and beaks submedian. Surface smooth and often glossy, occa- 

 sionally punctate. External ligament small, the internal resilium attached 

 to a posteriorly directed, oblique groove. Hinge with one or two cardinal 

 teeth and one or two posterior lateral teeth in each valve; pallial line 

 simple; surface sometimes covered by the mantle. 



Genus KELLIA Turton, 1822 

 Type species by subsequent designation, Recluz, 1844, Kellia subor- 

 bicularis (Montagu). 



Shell small or of medium size, thin, glassy, white, suborbicular and 

 strongly convex, the surface usually smooth, polished or with fine or strong, 

 concentric lines of growth. The umbones are prominent, subrnedian, the 

 small beaks incurved and prosogyrous. Hinge plate narrow, with a wide 

 notch in the middle bordered on each side by a small tooth, the anterior 

 one shaped like a cardinal tooth, the posterior one placed more distantly; 

 the left valve has two small divergent cardinal teeth with a socket or pit 

 between them, the right valve has a single cardinal only; both valves have 

 a flattened tooth at the posterior end of the median pit. Ligament is wholly 

 internal, the tensilium small, narrow, lying below the margin and above a 

 narrow nymphal lamina which distantly ends in a tooth, the resilium also 

 elongated in form and attached to a linear groove in the roof of the sub- 

 umbonal cavity. In some species, the surface is covered by a glossy, yellow- 

 ish periostracum. 



Kellla snborbicniarig (Montagu) Plate 33, figure 5; 



Plate 35, figures 6, 14 



Mya sub orbicularis G. Montagu, 1803, Test. Brit., pt. 1, p. 39. In hard limestone at Ply- 

 mouth, England, Suppl. 1808, pi. 26, fig. 6. 



Kellia suborbicularis (Montagu), W. Turton, 1822, Conch. Insul. Brit., p. 57. — Jeffreys, 

 1863, Brit. Conchology, vol. 2, pp. 225-229, pi. 5, fig. 3.— Dall, 1909, Proc. U. S. 

 Nat. Museum, vol. 37, No. 1704, p. 264. — Hertlein and Strong, 1947, Zoologica, 

 vol. 31, pt. 4, p. 133. 



Shell small (largest 5.5 mm.), suborbicular, with central umbones and 

 beaks, strongly convex, thin, subtranslucent or white, the surface smooth 

 or polished. As indicated by Hertlein and Strong, there seems to be no way 

 at present for the consistent separation of the Pacific shells from typical 

 examples of K. suborbicularis from Europe. 



Range — British Columbia southward to Peru. Also in the west Atlantic, 

 Caribbean, and European waters. Panama Canal Zone: Venado Beach. 

 Colombia: Isla del Gallo. Ecuador: Esmeraldas; Puerto Callo; Punta Cen- 

 tinella. Peru: Zorritos; Sechurita near Zorritos. 



Genus BOENIA PliilippI, 1836 



Type species by subsequent designation, Stoliczka, 1871, Bornia cor- 

 buloides Philippi. Recent, Mediterranean. 



The shell is usually small, subtrigonal to subelliptical, subequilateral. 

 The umbonal region is generally convex, the surface below often somewhat 

 impressed or flattened. Color white; surface smooth or minutely striate, 

 polished and sometimes faintly ribbed along the edge. The ligament has 



