The Tellen Shells. Sunset Shells. Wedge Shells 



area by a ridge running straight to the beak. Ridges radiate 

 from the beak on the inside of the shell. Striations under the 

 dirty epidermis sculpture the surface. Hinge ligament conspicu- 

 ous. Length, 3 to 4 inches. 



The Salmon-coloured Tellen (7. sdmonea, Cpr.; is a not- 

 able shell because on the outside it is white or nearly so, and inside 

 it is a rich salmon pink. The shell is thick, with glossy surface. 

 It is rectangular, the beaks at one corner and the ligament at one 

 end. Length, J inch. 



Habitat. — West coast. 



A complete series of west coast Tellens would include, besides 

 those described here, three or four species scarcely larger than a 

 finger nail. 



Genus MACOMA, Leach 



Shell oval, or almost round, convex; cardinal teeth narrow; 

 pallial sinus very deep. Gill with a single lamella on each side ; 

 palpi very large, triangular. Eighty-five living species. 



The Giant Macoma {M. secta, Conr.) leads the whole genus 

 in size. It will cover the palm of your hand. Note the flat, thin 

 and glossy shell, inequivalve, and bare of epidermis except at 

 the edges. The general shape is oval, with the posterior end 

 somewhat contracted, set off by a fold, and ending in a truncated 

 point. The broad ligament, which lies in a concave depression, 

 is conspicuous on the hinge line, back of the beaks. Length, 2 

 to 3 inches. 



Habitat. — Southern California. 



The Bent-nosed Macoma (M. nasuta, Conr.) has the pos- 

 terior end of its smooth white shell drawn out into a narrow ex- 

 tension, which is bent to one side. The moUusk lives in mud 

 flats, burying itself deeply, but keeping the tips of its red siphons 

 in the water above. This species is very much in evidence in the 

 shell heaps about San Francisco Bay, which still mark the site 

 of old Indian camping grounds. It was evidently the preferred 

 shell fish in the bill of fare of the aborigines. The sand clam, Mya 

 arenaria, an immigrant to these waters, seems to be replacing 

 M. nasuta to a considerable extent. The shell mounds show 

 not a specimen of this recent intruder. It is not easy to say why 

 the Macoma is dying out. Length, about 2 inches. 



Habitat. — Kamschatka to Mexico. 



34' 



