No. 1704. A COLLECTION OF SHELLS FROM PERU—DALL. i 
Or 
or 
ARCA (SCAPHARCA) LABIATA Sowerby. 
Arca labiata SowERBY, Proc. Zool. Soc. of London for 1833, p. 21.—Rrrve, Conch. 
Iconica, Arca, 1844, pl. 1, fig. 7. 
From the flats at Capon. 
Distribution.—From San Diego, California, south to Peru. 
Shell very small, but having the aspect of Arca grandis in minia- 
ture. Without close inspection it would be taken for the young of 
that species. It has no economic importance. 
GLYCYMERIS INZQUALIS Sowerby. 
Pectunculus inequalis SowERBY, Proc. Zool. Soc. of London for 1832, p. 196 
(not of Zool. of Beechey’s Voy., 1839, pl. 32, fig. 3) —Rrrve, Conch. Icon., 
Pectunculus, pl. 4, fig. 16. 
Dredged in 5 fathoms, Sechura Bay, west of Matacaballa. 
Distribution —Gulf of California to Sechura Bay, Peru. 
Shell subcordate, solid, heavy, with obtuse radial ridges; lilac 
gray or white with four or five broad rusty or blackish transverse 
bands, irregularly disposed; interspaces of the ribs striated; liga- 
ment short and a very small part of it behind the umbones. 
This species is rare and too small to have any economic value. 
GLYCYMERIS OVATA Broderip. 
Pectunculus ovatus Broperip, Proc. Zool. Soc. of London for 1832, p. 126.— 
REEVE, Conch. Icon., Pectuwnculus, 1843, pl. 1, fig. 2. 
Dredged in Callao Bay, near San Lorenzo Island. 
Distribution —Coquimbo, Chile, northward to the Lobos Islands, 
Peru, in 17 fathoms. 
Shell obovate, convex, smooth, white, with fine transverse lines; 
the umbones pale chestnut, the interior white with a crenate margin. 
Periostracum thin, velvety, olive brown. 
This species has no economic value and is rather uncommon. 
ALIGENA COKERI, new species. 
Plate 28, figs. 5, 6. 
Attached to worm tubes thrown upon the beach of the lagoon at Capon, Peru. The 
worms live in the beach. The tubes resembled those of Chetopterus. 
Shell small, white, thin, very fragile, tumid, more or less medially 
constricted; beaks full, high, closely adjacent, slightly anteriorly 
twisted and somewhat in advance of the middle of the shell; valves 
rounded quadrate, with a wide shallow furrow or constriction extend- 
ing from the vicinity of the beaks to the middle of the base; ends 
rounded, base mesially excavated; sculpture consisting of concen- 
tric incremental lines and sparser, little-elevated, concentric threads; 
