ZOOLOGY. 
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long and slender, and the whorls more convex ; the aperture ovate instead 
of roundish-ovate. The specimen brought home appears to be young . 
Class. CoNCHOPHORA. 
Order. — Pachypoda. 
Fam. — M yadejE. 
Genus. — Mya. Lin. 
Species. — Mya truncata. 
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Order. — Leptopoda. 
List. Conch, t. 428, f. 269. 
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Fam. — NucuLiDiE. 
Genus. — Nucula, Lamarck. 
** Shell behind slightly produced, gaping ; edge entire. 
Species. — N. arctica. 
Testa ovali-elliptica, laevis, tenuis, fragilis, flavescens ; latere antico lato, 
rotundato, postico brevi, oblique truncato. 
Nucula arctica, Gray ut supra. 
Shell oval-elliptical, smooth, very slightly concentrically wrinkled ; epidermis 
yellowish -green, glossy ; umbones rather acute, nearly central ; broad 
rounded, rather narrowed, obliquely truncated behind ; inside glossy-white, 
edge plain in front; length (from front to back) half an inch; depth (from 
umbones to the opposite edge) a quarter; breadth (from the outside of one 
valve to the outside of the other, in the most convex part) one-sixth. 
* * * Shell behind much produced, gaping, above depressed. 
Species. — N. rostrata, Lamarck Hist., vi., 58. 
Area minuta, O. Fabr., Faun. Grcenl., young ? 
.. 
sfioici 
-not. Mont; 
Area rostrata, Chem. Conch., vij . 1 06. t. 55. f. 550. 551 , 
Shell, length 7-8ths, depth 3-8ths, breadth 2-8ths, of Un inch. 
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Animal, Mantle-lobes, separate from one another ; foot compressed, sub- 
quadrate, front rent; gills attached to the hinder part of the mantle, as in 
the Pholades and Myae, 
Order. — Phyllopoda. 
Fam. — Hyatellad^:. 
