LIST OF IRISH TESTACEA. 



20. nitidissi- 

 miis. 



21. Terebra. 



22. nigricans. 



Musco- 

 rum. 



in a sharpened apex. The first, or body- 

 whorl, is completely detached from the other 

 volutions. It has two very elevated spiral 

 ribs, running from the base to the apex, at 

 the base and centre of the whorls, the lower 

 one giving a strong division to the spires ; 

 the whorls are strongly wrinkled longitudi- 

 nally; aperture perfectly round. Colour of a 

 deep chestnut. When viewed from the base, 

 the detached or body volution gives it the 

 appearance of being deeply umbilicated. 

 Length, | inch ; breadth 



One specimen of this new shell was found in 

 Dublin Bay by Dr Turton. 



Montagu, Test. Br. p. 209. t. 12. f. 1.— Linn. 

 Tr. viii. p. 175. Portmarnock, rare. 



Montagu, Test. Brit. p. 293.— Donovan, Br. 

 Sh. t. 22. f. 2. Dublin Bay, Portmarnock, 

 and Killough ; common. 



Donovan, Br. Sh. t. 72. T. perversus. — Mon- 

 tagu, Test. Br. p. 357- t. 11. f. 7. T. bidens. 

 On a mossy stone at Clonooney ; in old walls 

 at Ferbane ; and near Downpatrick. 



Donovan, Brit. Sh. t. 80. — Montagu, Test. Br. 

 p. 335. ; Supp. t. 22, f. 3, In the crevices 

 of a large mossy stone, Clonooney ; in an old 

 wall near Ferbane ; and in the sand-banks at 

 Portmarnock Burrow, very plentiful. 



HELIX. 



1. Lapicida. Montagu, Test. Br. p. 435. — Donovan, Brit. 



Sh. t. 39. f. 2. In the neighbourhood of Bel- 

 fast by Dr Macdonnell. 



2, Planorbis. Linn. Trans, viii. p. 188. t. 5. f. 13. — Montagu, 



Test, Brit. p. 450. H. complanata ; Supp, 

 L 1 4 



