158 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 37. 



CHIONE ASPERRIMA Sowerby. 



Venus aspemma Sowerby, Proc. Zool. Soc. of London for 1835, p. 42; Thes. 

 Conch. Venus, 1853, pi. 155, figs. 57-58. 

 From the shell heaps at Huaquilla and Matapalo. Common in some localities, 

 especially shelly beaches. "Concha tabaco" of the fishermen, who do not like it, 

 saying it has the flavor of tobacco. 



Found associated with the Anomalocardia. 



Distribution. — Gulf of Cahfornia southward to the Lobos Islands, 

 Peru. 



Shell rounded triangular, moderately tumid, whitish or grayish, 

 with fine, rough, reticulate sculpture; in favorable localities with 

 brown or livid varied painting on a lighter ground; lunule ovate, 

 depressed, whitish. 



This shell is recognizable by its rasp-like surface and long anterior 

 cardinal tooth. 



CHIONE COMPTA Broderip. 



Venus compta Broderip, Proc. Zool. Soc. of London, for 1835, p. 43. — Sowerby, 

 Thes. Conch. Venus, 1853, pi. 154, figs. 32-34. 

 Beach of Sechura Bay, near Matacaballa. 



Distribution. — Gulf of California and southward to the Galapagos 

 Islands and Sechura Bay, Peru. 



Shell closely resembHng GJiione canceUata of the Atlantic coast, 

 but flatter, more spread at the sides where the radiating threads are 

 divergent, and the concentric sculpture is more laminar and less 

 reflected; the latter is apt to be crowded, ventrally, in senile exam- 

 ples. The shell is white, rounded trigonal, solid, and heavy, with 

 radiating rounded threads and concentric more or less distant 

 lamellge. The internal margins are crenulate, and the shell rarely 

 exceeds 30 mm. in length. It is too small and not sufficiently abun- 

 dant to have an economic value. 



ANOMALOCARDIA SUBRUGOSA Sowerby. 

 Plate 26, fig. 3. 

 Venus subrugosa Sowerby, Genera of Shells, 1834, fig. 2. 

 Conchas de los bajos. Near Capon, at the oyster beds of Matapalo, there is along 

 the border of the mangrove swamp a shelly bank about 25 meters wide. P>om this 

 thousands of these shells may be taken in a short time. They are esteemed as food 

 by the fishermen. They were also taken at Lancha de Fierro, at the mouth of the 

 Tumbes River, and in the tidal lagoon La Boca Grande, at Tumbes; and the dead 

 shells occur in the shell heaps at Huaquilla, on the Ecuador border. 



Distribution. — From the Gulf of Cahfornia to Valparaiso, Chile. 



Shell ovate, subcordate, very tumid, tliick and solid, the ventral 

 edge much arcuated; color pale, with three or four dark rays; a few 

 large, coarse, smooth, rounded and concentric ribs which become 

 obsolete on the anterior slope and toward the ventral edge; lunule 

 cordate, hmited by an impressed fine; inner margins crenated; 

 length about 35 mm. 



