SPARTZBRANCHIA. 209 
convex. Operculum testaceous, produced into an angle be- 
hind, with the nucleus central. 
1. BiIrHyNIA JACULATOR. 
B. testa anfractibus sex moderatim tumidis ; sutura moderatim 
profunda. 
Helix tentaculata, Linn. Syst. Nat. xxu. 1249; Faun. Suec. 
2191; Penn. Brit. Zool. 140. t. Ixxxvi. f. 140; Chem. 
Conch. ix. t. exxxv. f. 1245; Pult. Cat. Dorset, 49. t. xx. 
f.12; Donov. Brit. Shells, t. xcii.; Mont. Test. Brit. 389 ; 
M. & R. Trans. Linn. Soc. viii. 220; Dill. Dese. Cat. 882 ; 
Turt. Conch. Dict. 68. 
Nerita jaculator, Mill. Verm. ii, 185. no. 372. 
Turbo nucleus, Da Costa, Brit. Conch. 91. t. v. f. 12. 
Turbo pullus, Walk. Test. Min. Rar. f. 33. 
Cyclostoma impurum, Drap. Hist. des Moll. Terrest. et Fluv. 
amt. 1. 7. 19. 
Limneea tentaculata, Flem. Edinb. Encycl. vii. 78. 
Animal cinereum, caput et collum flavo-punctata. Tenta- 
eula cinerea, pallida, olivaceo-irrorata. Pes superné pallidé- 
nigricans, margine pallidiore aut cinereo, flavo-sparso punctis 
seepissimé confluentibus. 
Habitat in fluviis. Alt. 4 unc. 
Shell moderately elevated, with six whorls moderately tumid. 
Suture moderately deep. Height half an inch. 
Animal ash colour, head and neck spotted with yellow. 
Tentacles ash colour, pale, sprinkled with olive. Foot pale 
black above, margin paler or grey, spotted with yellow. Spots 
generally confluent. 
Inhabits rivers. The Thames, the Avon, and the Exe. 
2. Biruaynia LEACHII. 
B. testa alté elevaté; anfractibus quinque ventricosis; sutura 
valdé profunda. 
Turbo Leachii, Shep. Trans. Linn. Soc. xiv. 152. 
Animal cinereum, caput et collum superné nigrescentia, fla- 
vido-punctata. Tentacula longissima, cinerea, pallidé olivaceo 
