2G2 PROCEEDINGS OP^ UNITED STATES NATIONAL MUSEUM. [1885. 



about 9, of whicli there are generally o larger tbau tlie rest, their tips 

 nearly meeting and their bases mutually nearly equidistant; one is on 

 the pillar, one on the body whorl, and one on the anterior margin ; on 

 either side of the latter are two generally subequal much smaller den- 

 ticles. Lon. 1.60, lat 0.75'""'. 



Hahitat. — Under loose oak bark, oak hamak, Archer, Alachua County, 

 Florida, April, 1885, W. H. Ball, sixteen specimens. 



This is one of our smallest species and is related to P. peniodon and 

 P. pellucida. It is about half the size of the former and much more 

 slender. Its teeth recall those of P. curvidens Gould in their arrange- 

 ment, but the shell is more cylindrical and smaller, as it is than in P. 

 2)ellucida {servilis) as figured by Gould. The teeth are more numerous 

 than in the latter shell, and set, as in P. pentodon, in one series ; not, as 

 in pellvAiida, partly deeper in the throat. 



I describe this with some hesitation, for the condition in which the 

 Pupidie and Yertigos of North America are is most unsatisfactory and 

 ofiers an excellent field to some careful student who shall be able to 

 examine and figure large series of authentic specimens. Still, as there 

 is absolutely no other form with which I feel able to unite this one, it is 

 better to give it a name than to leave it erroneously with some other 

 species. 



Vertigo ventricosa Morse. 



Isihmia ventricosa Morse, Aun. N. Y. Lye. Nat. Hist., viii, p. 1, figs. 1-3, 1865, 

 Biimey, 1. c., p. 218. 



Six specimens of a small Vertigo were found under the bark of a de- 

 caying oak log at Archer, Alachu.i County, Florida, and two others on 

 dead leaves at Enterprise Lake, Monroe, Fla., which seem referable to 

 this species. They have, however, six or seven teeth like V. ovata Say, 

 while the dimensior.s are those of Morse's species. Two of them are so 

 enrolled that only one whorl above the body whorl is visible except from 

 above, as if the apex had been crowded vertically downward. Similar 

 distortions are not very uncommon among these small shells. In this 

 connection Mr. Binney's figure of Pvpa alticola IngersoU (1. c, p. 212, 

 fig. 116) may be noticed. While it doubtless represents the specimen fig- 

 ured, there is equally no doubt that that specimen was abnormally dis- 

 torted. Specimens marked typical by Mr. IngersoU in the museum col- 

 lection do not show any such disproportion in the last whorl, though 

 there is visible a slight constriction of the last whorl but one, in many 

 individuals of this species, as well as in many full grown specimens of 

 Vertigo simplex Gould, with which it is probably synonymous. 



Strobila labyrinthica Say. 



Helix lahyrinihica Say, Jonrn. Acad. Nat. Sci. Phil., vol. i, p. 124, 1817. 

 Strobila Jahyrinthica Morse, 1864, Binuey, 1. c., j). 259, 1878. 

 Helix Slreheli Pfr., Mai. BL, 1861, p. 71, pi. 1, figs. 5-8. 



Habitat. — Mirador, Vera Cruz, Mexico, Pfr. ; Eastern United States, 

 Biimey; Florida, Jewett, Stearns; Sarasota Bay, Florida, Hemphill; 



