188 INVERTEBRATA OF MASSACHUSETTS. 



lijD, equidistant ; one with a tubercle at its base, on the middle of 

 the left lip, and nearly at right angles with the former is the 

 largest ; a fourth is on the indenture of the outer lip, directed 

 between the two on the transverse lip, and two smaller ones, 

 more retired within the shell, are equidistant between the two last 

 mentioned ; umbilicus large and deep. Length less than 3'^ inch, 

 breadth ^\ inch. 



This shell I first found in November, 1839, at Oak Island, 

 Chelsea, after a warm rain. Professor Adams has found it in 

 Vermont. It was crawling on the damp leaves, in company with 

 Bullmus lubricus. 



Not finding any description answering to it, I have proposed a 

 name. It is even more minute than P. exigua, and is not readily de- 

 tected. In size and outline it resembles P. vertigo, Drap., V. pusilla 

 of other authors ; but that shell is reversed, and has a different arma- 

 ture. The teeth are all distinct, long, compressed, and very sharp. 



I have labored to make this out to be the P. ovata of Say ; but 

 on the whole I think the discrepancies are too important to be recon- 

 ciled. That shell is described as larger, with a semi-oval aperture, 

 and with seven teeth, differently arranged from those of our shell. 



Pupa mode'sta. 



Shell ovate-conic, amber-colored ; whorls five or six, convex, 

 wrinkled; aperture semi-oval, broader than long ; teeth Jive; um- 

 bilicus distinct. 



Figure 119. 



State Coll., No. 90. Soc. Cab., No. 2.397. 



Pupa mode'sta, Say ; Long's Second Expedition, Jppend., ii. 2.59, pi. 15, f. 5. 



Shell minute, ovate-conic, thin, amber-colored ; whorls five ; 

 sometimes six, minutely wrinkled, well rounded, and defined by a 

 deep suture, gradually diminishing to a rather acute apex ; aper- 

 ture about half the breadth of the last whorl, slightly oblique ; 

 rather broader than long ; semi-oval, but modified by an inflection 

 of the outer lip ; lip simple, not reflected, joining the preceding 

 whorl behind, by a curve ; teeth five, slender, sharp and direct, like 

 the teeth of a comb ; one on the middle of the transverse lip, a 

 still larger one at right angles on the middle of the pillar lip, a 



