COLIMACEA. MOLLUSCA. PUPA. 191 



The only locality where this has been hitherto found is a small 

 grove, a little northward of Fresh Pond, in Cambridge. In this 

 place it has been found among the moist leaves, on three succes- 

 sive visits in the months of May and June, in company with 

 Helix linedta, Inbynnthicay cfiersina, and indentdta, and Pupa mo- 

 desta. None of the shells exhibit 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 infringe- 

 ment of the last whorl but one on the aperture, we might rather 

 refer the shell to Cyclostoma than to Pupa. 



It is rather smaller than P. modesta, and about the size of P, curvi- 

 dens ; but the simplicity of the unarmed, circular aperture distinguish 

 it from every American species. The aperture of P. modesta, before 

 the developement of the teeth, is broader than long. It is the analogue 

 of the Vertigo edentula of Europe. 



Pupa exi'gua. 



Shell minute^ whitish, ohlong-uvate, rather pointed; whorls 

 Jive ; the transverse Up very oblique, with a small fold near its 

 internal angle ; outer lip widely rejiexed. 



Figure 122. 



State Coll., No. 290. Soc. Cab., No. 2416. 



Pupa exigua, Say ; Journ. Acad. JVht. Sc , ii. 375. Gould ; Bost. Journ. jYat. 

 Hist., iii. 398, pi. 3, f. 20. 



Shell elongated, pellucid, tapering somewhat to both ends, apex 

 not very blunt ; color watery-white ; whorls five, rather convex, 

 very oblique ; suture very distinct ; aperture obliquely oval ; 

 transverse lip very oblique, and having, near its inner termination, 

 a small, tooth-like fold ; another very small, tubercular tooth is 

 found at the middle of the pillar ; outer lip white, widely reflect- 

 ed, but not flattened. Length -^-^ inch, breadth ^V inch. 



A few specimens have been found in Cambridge, by Mr. T. J. 

 Whittemore, under boards, in damp places. Professor Adams 

 has found it in Vermont, and it is common in Ohio. 



This very minute species, is principally remarkable for its long, 

 tapering form, large and very oblique aperture, and broadly reflected 



