23 



PHYSA HETEROSTROPHA, Say. 



Plate 1.— Pl. 2, Figs. 1—9. 



P. testa ovatii, vel elonsata, fusca vel castanea: anfrac- 

 tibus 4 — 5 convexis: sutura conspicua. 



SYNONYMS AND REFERENCES. 



Lister, Conch., pi. 135, fig. 34. 



Sciiroter, Einl., vol. i. p. 201, Helix no. 84. Say. 



Lymnea HETEROSTROPHA, Say. Nich. Encyc. (Am. ed. 



Art. Conch.) pi. i. fig. 6. — Physa heterostropha, Say, 



Jour. Acad. Nat. Sci., vol. ii. p. 177. 

 P. heterostropha, Gould. Invert, of Mass., fig. 141. 

 Physa heterostropha, Desh. in Lam., vol.viii. p. 402. 

 Bulla fontinalisI Indite orientalis, Chemnitz. 



Conch., vol. ix. pi. 103, fig. 879, 880. 

 Bulla crassula 1 . Dillwyn. Cat., p. 487, no. 36. 

 Physa aurea,1iEa. Tr. Am. Phil. Soc, vol. iv. 



DESCRIPTION. 



Animal dark yellowish-grey, minutely dotted 

 with whitish-yellow: foot, when extended, longer 

 than the shell. When the shell is light color- 

 ed, the animal is wine-yellow, dark yellowish- 

 grey above, with a conspicuous spot upon each 

 side of the forehead, made up of minute dots of 



