204 Dr. Leach on the new Arctic Animals [Sept. 



In its general form it is allied to my Pandora obtusa ; (Solen 

 Pinna, Mont.) a species net uncommon in the Sound of Ply- 

 mouth, but it may be readily distinguished by the superior size 

 of the teeth of the hinge. 



Family III. — Veneridx. 



Genus Macoma (Leach). 



Char. Testa compressiuscula aequivalvis, clausa, longior 

 quam alta: Umbo postice vix prominens: Cartilago externa: 

 valva dextra dentibus 2 fissis, sinistra dente 1 integro. 



Species Tenera, concentrice elevato-striolata, epidermide 

 viridescente-lutea. Lat. 76° N. ; long. 76° W. Taken up with 

 the soundings. Received also from the coast of Spitzbergen. 



Genus Crassina (Lamarck). 



Species 1. Scotica. — Venus, Scotica Maton and Racket. Lat. 

 62° N.; long. 62°. Taken up in 80 fathoms water. It differs 

 in no respect from those taken on the southern coast of Devon- 

 shire, excepting in being rather smaller. 



Species 2. Semisulcata, concentrice striolata ante medium 

 usque ad umbones sulcata. The colour is much darker than in 

 C. Scotica. A broken specimen only occurred in Baffin's Bay, 

 but several in good condition were found amongst soundings on 

 the coast of Spitzbergen. 



Genus Nicania (Leach). 



Char. Testa triangulato-orbicularis, aequivalvis, clausa : 

 Umbo prominens : cartilago externa : Valva dextra dente uno 

 valido bifido ; sinistra dentibus duobus integris divaricatis. 



Species 1. Banksii, glabriuscula polita, sub umbonibus 

 impresso-excavato. Baffin's Bay, amongst soundings. Received 

 also from the Spitzbergen coast. 



Species 2. Striata, concentrice striata, sub umbonibus cor- 

 dato-impressa. Lat. 76° 42' N. ; long. 76° W. 



Family IV. — Pinnid.e. 



Genus Modiola (Lamarck). 



Species 1. Arctica, alta, radiatim late striata. Baffin's Bay, 

 on Hare Island, and among soundings. 



Species 2. Discrepans. — Mytilus discrepans (Montagu). 



A fragment of a large specimen differing in no degree from 

 those of Scotland, occurred amongst the soundings from Baffin's 

 Bay. 



Genus Mytilus (of authors). 



Species Pellucidus (Pennant). 



Found on Hare Island, by Mr. Beverly. 



