PLATE LI. 



Helix Stagnalis : testa imperforata ovata-subulata, subangulata, 

 apertura ovata. Linn. Syst. Nat. p. 1249. 

 No. 703. 



Cochlea testa producta acuminata, opaca, anfractibus senis subangu- 

 latis, apertura ovata. Linn. F. Suec. I. p. 374. 

 No. 1310. //. No. 2188. 



Buccinum longum sex spirarum, omnium & maximum Sc produc- 

 tius, subflavum, pellucidum, in tenue acumen ex 

 amplissima basi mucronatum. Turbo laevis in 

 stagnis degens. Aldror. de Testaceis, I* 3. 

 p. 359. No. 3. 



Buccinum subflavam pellucidum, sex orbium, clavicula admodum 

 tenui, productiore. List. II. Conch, tab. 123. 



fig' 21 - 



Buccinum minus fuscum, sex spirarum, ore angustiore. List. H* 

 An Angl.p. 139. tit. 22. tab. 2. fig. 22. 



Helix Stagnalis. Lake. Penn. Br. Zool. No. 136. tab. 86. Jig. 136. 



Fresh water turbo with six wreaths. Wallis Northumb. p. 369. 



Turbo longus et gracilis in tenue acumen mucronatus, imperforatus 

 & pellucidus Stagnalis. Da Costa Br. Conch, 

 p. 93. sp. 52. tab. 5. fig. 11. 



The largest and most produced of the British river snails, and is 

 found in plenty in all our rivers, lakes, ponds, and other waters. 



Lifter and Petiver have made two species of this shell maximum 

 and minus ; they appear however to be merely different stages of its 

 growth. 



