190 PROCEEDINGS OF THE ACADEMY OF 



siana (fig. 35) has 88 rows of 12—1 — 12 teeth, with 6 perfect late- 

 rals. A comparison of this description and figure with that of 

 Lehinann, pi. XIV., fig. 53, will prove that this species cannot be 

 identical with P. pj/gmaea of Europe, as has been suggested by 

 Mr. Gwyn Jettreys (Ann. Mag. Nat. Hist., 1872, 246). 



i^^&m 



(300^3 



c:? 



C3l 



Fig. 35. 



Lingual dentition of Vertigo Gouldi. Lingual membrane of Vertigo Bollesiana. 



[Morse.] [Morse.] 



V. milium^ not observed. 



F. ovata (see above figure 33) has 90 rows of 14 — 1 — 14 teeth 

 apparentlj' with 9 perfect laterals. The species has been referred 

 to P. antivergo, but the figure of the dentition of that species given 

 by Lehmann (pi. XIV., fig. 52) does not sustain the theory of iden- 

 tity. 



V. ventricoi^a has 98 rows of 13 — 1 — 13 teeth, with 6 perfect 

 laterals (fig. 36). 



V. simplex, not observed. 



Fig. 36. 



Lingual membrane of Vertigo ventricosa. [Morse] 

 Genus STROPHIA, Albers. 



But one species, S. incana, Binn., is found within our limits. I 

 have found it to agree in the characters of its jaw and lingual 

 membrane with the extralimital species which I have examined, S. 

 iostoma, mumia, and decumana. Semper, however (Phil. Arch. 

 128), describes the jaw of S. tiva as being without median projec- 



,,. „ tion to its cuttina: edge : that character, therefore. 



Fie;. 87. o & ; 7 : 



cannot be considered generic. 



Jaw of S. incana (fig. 37) arcuate, thick, coarse, 

 of about equal height to its bluntly truncated ends: 

 cutting edge with a slightly produced median pro- 

 jection. Anterior surface without ribs. 

 Fig. 38 shows the general arrangement of the teeth upon the 



