ccxlii 
APPENDIX. 
Genus. — Hyatella. Dandin. 
Species. — H. Arctica. Lamarck, Hist. vj. 
Mya arctica. 0. Fabricius, Faun. Groenl., 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., 408. 
Mya pholadis. Linn. 
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^e. 
Genus.— Glycimeris. Lamarck. 
Species. — G. siliqua. Lam. Hist., v. 458. 
Solen siliqua. Chemn. Conch., xi, 192. t. 196. f. 1934. 
Fam. — Veneridje. 
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 
