444 HELICID-E. 



Maine, New Hampshire, and New York. 



I have not seen this species. Mr. Morse says it has been eon- 

 founded witli V. ovata, but is one fourth smaller, has one whorl 

 less, and a more circular columellar margin to the aperture, &c. 



Vertigo simplex. 



Fig. 121. 



Shell minute, cylindrical-ovate, smooth; whorls five; aperture circular, tooth- 

 less; umbilicated. 



Pupa simplex, Gould, Bost. Journ. Nat. Hist. Hi. 40.3, pi. 3, fig. 21 (1840) ; iv. 3.59 (1843) ; 



Inv. 190, fig. 121 (1841). — Pfeiffer, Mon. Hel. Viv. ii. 302. — De Kay, N. Y. 



Moll. 52, pi. 36, fig. 347 (1843). — Bixnev, Terr. Moll. ii. 343, pi. 72, fig. 3. 

 Vert'ujo simplex, Stimpsox, Shells of New England, 53 (no descr.). — W. G. Binney, 



Terr. Moll. iv. 148. — Mokse, Am. Nat. i. 670, figs. 67, 68 (1868). 



Shell minute, two thirds of the shell cylindrical, surmounted 

 by a rapidly formed, blunt apex, smooth, light chestnut colored. 

 j,j„ ^^jg Whorls five, moderately convex, separated 



by a distinct suture, quite smooth ; aper- 

 ture circular, except for a small section 

 from the posterior portion, which is cut 

 off by the encroachment of the preced- 

 ing whorl ; lip simjde and sharp, slightly 

 everted on the left side, and i)ai'tially 

 hidino; a small umljilicus. No trace of 

 a tooth has liecn detected in any of the specimens examined. 

 Length, one fiftoonth of an inch ; breadth, one thirtieth of an inch. 

 The locality where this was first found is a small grove, a little 

 northward of Fresh Pond in Cambridge. In this place it has been 

 found among iho, moist leaves, on three successive visits in the 

 months of May and Juno, in company with Heli.c lineata, labyrin- 

 thica, chejsina, and indcntata, and Pupa modcsla. None of the 

 shells exhil)it any trace of a tooth, although their aspect, and the 

 season of the year, indicate that they can be none other than adult 

 shells. Indeed, were it not for the infringement of the last whorl 

 but one on the aperture, we might rather refer the shell to Cijclos- 

 toma than to Pupa. It occurs in Canada and New England. 



It is rather smaller than P. nwdesta, and about the size of P. 

 pentodon; I)ut the simplicity of the unarmed, circular aperture dis- 

 tinguishes it from every American species. The ajierture of P. mo- 

 dcsta, l)cfore the development of the teeth, is broader than long. 

 It is the analogue of the Vertigo edentula of Europe. 



