MACOMA. 93 



three fourths inch; height, three fourths of an inch; breadth, eleven 

 twcntietlis of an incli. 



Sent to me by Dr. L. j\I. Yale from Martha's Vineyard. Gull 

 Island (^ Smith}. 



It is a proportionally shorter and broader shell ; but its most 0I3- 

 vious mark of distinction is the want of an areola l)efore the beaks. 



[Dr. Stimpson remarks : " I have found the differences between 

 this and the preceding species, mentioned by Dr. Gould, to be hi- 

 constant." There is much doubt in my own mind also in regard 

 to its title to a separate name, as I have seen no extended series 

 for comparison. The shell figured in Sowerby's Tliesaurus is widely 

 different from this, and is probably a South American species. 



Family TELLINID^, Latreille. 



Not more than two cardinal teeth on the same valve ; a lateral 

 tooth each side when not obsolete ; ligament on the shorter end ; 

 pallial sinus very large ; animal with long slender separate siphons ; 

 mantle open. 



Genus MACOMA, Leach. 1819. 



Shell equivalve, sub-ovate, compressed, rounded anteriorly, sub- 

 rostrate posteriorly, slightly gaping at ends, with posterior sub-mar- 

 ginal flexure ; hinge with two small cardinal teeth in each valve ; 

 pallial impression with a deep sinus. Animal with one simple 

 frinu'c on each side. 



'O" 



Macoma fusca. 



EiG. 42. 



Shell compressed, ovate-orbicular, sub-equipartite, rounded before and some- 

 what pointed behind; white, covered with a dusky epidermis; teeth, two in 

 each valve, the largest of which is grooved. 



Lister, t. 405, fig. 250. 



Psawmohi.(j fasca, Say, Journ. Acad. Nat Sc. v 220 (1826). 



Sunyuinolaria fusca, Coxrad, Aiiier. Mar. Conch. 34, pi. 7, fig. 1 (1831). — Stimpsox, Sh. 

 of New Eng. 20 ; Tnv. Gr. Man. 2d ed. 21. — Gould, Inv. Mass. 1st ed. 66. -De 

 Kay, Nat Hist. N. Y. 212, pi. 32, fig. 304. — Mighels, Bost. Journ. N. H. iv. 317. 



Tellina fusca, Phil. Abbild. t. 3, fig. 3. 



Tellina inconspicuu? Sowerby, Zool. -Journ. iv. 359. — Gray, Zool. Beech. Voy. 153, pi. 

 41, fig. 6. — Hanley, in Soweruy, Thes. Conch. 317, pi. 59, fig. 120. 



Tellina Gronlandica, Beck, see Lyell, Tr. Gcol. Soc. Lond. 1841, vi. 137, pi. 16, fig. 8. 



