ccxlil 
APPENDIX. 
Genus. — Hyatella. Daudin. 
Species. — H. Arctica. Lamarck, Hist. vj. 
My a arctica. O. Fabricius, Faun. Grcenl., 407. 
Animal, Mantle-lobes, united together, except leaving a small ovate aper- 
ture for the passage of the foot, on the lower side, near the front. Tubes 
2 distinct. 
Genus. — Saxicava. Lamarck. 
Species. — S. pholadis. Lam. Hist., v. 502. 
Mya byssifera. O. Fab., Faun. Green., 4^08. 
Mya pholadis. Limi. 
Shell differs from S. rugosa by its larger size, and being more produced and 
acute in front, and in having deeper concentric furrows ; length 1 inch and 
3-4ths, depth 3-4ths, breadth l-4th. 
Animal, like that of Hyatella arctica. 
Family. — Solenid.®. 
Genus. — Glycimeris. Lamarck. 
Species. — G. siliqua. Lam. Hist., v. 458. 
Solen siliqua. Chemn. Conch., xi, 192. t. 196. f. 1934. 
Fam. — Venerid^e. 
Genus. — Nicania. Leach. 
* Margin of the valves even. 
1. N. striata. Leach. Ross's Voyage. 
Shell, length 3-4ths of an inch, depth one-half, breadth 3-4ths. 
(Nicania Banksii of Dr. Leach belongs to this section.) 
** Margin of the valves crenated. 
2. N. crenata. 
Testa ovali-elliptica, virescens, concentrice sulcata; lunula oblongo-lan- 
ceolata impressa ; margine crenulato. 
Nicania crenata. Gray ut supra. 
Shell oval, elliptical, regularly concentrically furrowed ; epidermis pale 
yellowish green ; umbones nearly central, front, with an oblong lanceolate 
