105 



and numerous sharp pointed lateral comb-like teeth; 

 ligament inter naL 



* Margin crenulated. 



N. NUCLEUS. Turt. B.p. 176. t. 13. /. 4. F. p. 

 401. ARCA. N. Lin. 1143. Pew. 4. p. 217. Don. 

 2. t. 63. Mont. p. 141. Lin. T. 8. p. 95.- Dor. 

 Cat. p. 37. 1. 12. / 6. D.p. 244. TV*. >..p. 8. 

 Da Cos. *. 65./. 62. (rt. hand.) C%./.,574. N. MAR- 

 GARITACEA. Zam. 6. Obliquely subcordifovm, subtri- 

 angular, anteriorly produced, cuticle blackish or dark 

 olive green, (at times with yellowish rays and very 

 minute striae) glossy; lunuleoval; inside silvery, teeth 

 about twenty anteriorly, about ten posteriorly ; margin 

 crenated. 0,40... i. Common. 



N. TENTHS. Turt. B. p. 177. F. p. 402. ARCA. 

 T. Mont. Sup. p. 56. t. 29./. 1. Pen. 4. p. 218. 

 D. p. 246. Turt. D.p. 1 1 . Obliquely-heart-shaped, 

 roundish and nearly smooth, produced and rounded 

 anteriorly, white or covered with a thin olive skin ; 

 inside white, a little pearly, margin entire. i...f. 

 Scotland. ,fcj 



N, ROSTRATA. Turt. B.p. 178. F. p. 402. 



u- 3 'V-ria^ 



