VERTIGO. 173 



Inhab. marshy situations, on Isolepis Jluctuans. 

 {Gray, 1817.) 



Animal grey-black and shining ; upper tentacles 

 short, inflated at the base, lower dot-like ; front of 

 head proboscis-like. 



Shell smaller than the last, of a deep chestnut- 

 brown colour, with the margin of the ai)erture 

 whitish ; teeth three above and three below, and one 

 on each side, and often a ninth tubercular tooth. 



It may easily be distinguished by the three very 

 discernible white teeth of unequal size within the 

 upper and truncated part of the aperture, whereas 

 there is only a single central one apparently visible 

 in the same position in V. pygmcBa, and two in V. 

 suhstriata. The mouth varies with from six to nine 

 teeth. 



b. Shell cylindrical fusiform, sinistral; mouth mar- 

 gined externally. (Vertigo Milller. Vertilla 

 Moq. Tand.) 



80. 7. Vertigo pusilla. Wry-necked Whorl Shell. 



— Shell ventricose, attenuated, bald, rather 



shining, very brittle, pale brown ; whorls five ; 



mouth subquadrate, rounded beneath ; plaits 



six or seven, white, two or three on the column, 



and four on the lips ; peristome thin ; umbilicus 



rather narrow, (t. 7. f. 86.) 



Vertigo pusilla. Midler, Verm. ii. 124. ; Alder, Mag. Zool. 

 and Bot ii. 112. ; Jeffreys, Livn. Trans, xvi. 361. — Jaminia 

 heterostropha. Ris.so, iv. p. 91. — Vertijro beterostropha. 

 Turioi), Man. 105. f. 88. ; Leach, Mall. Syn. 94. — Pupa 

 Vertigo. Drap. Tabl. 57., Hist. Moll p. 61. t. 3. f. 34, 35. 

 — Pupa pusilla. L. Pfeiffer, Mori. H. ii. 364. ; Forbes and 

 Hanley, B. M.'w. 111. t. 130. f. 8. — Helix Vertigo. Gmel. 

 S. N. 3664. —Turbo Vertigo, var. Mont. T. B. 365. 



