248 



LAND AND FRESH-WATER SHELLS OF N. A. [PART T. 



(24 — 1 — 24) ; central with a median cusp and two blunt obsolete 

 cusps at its side ; lateral teeth bicuspid ; uncini serrate. 



Some individuals have also internal denticles in the upper 

 whirls (see Pfeifler, Mai. Blatt. 1859, 209, pi. ii, f. 1-3). 



Doubtful and Spurious Species of Pupa. 



Pupa placida, Say, is probably an accidentally introduced specimen of 

 BiiUminiis obscurus, MiJLLER (see Boston Proc. I, 105). The original 

 description here follows : — 



Shell dextral, cylindric-conic, pale yellowish horn-color ; apex 

 whitish, obtuse ; whirls six and a half, somewhat wrinkled ; suture 

 moderately impressed ; aperture unarmed, longitudinally oval, 

 truncate a little obliquely above by the penultimate volution ; 

 columella so recurved as almost to conceal the umbilicus ; labrum, 

 with the exception of the superior portion, appearing a little re- 

 curved when viewed in front, but when viewed in profile, this 

 racurvature is hardly perceptible ; umbilicus very narrow. 



Length over three-tenths of an inch. Inhabits Massachusetts. 



For this shell I am indebted to Dr. T. W. Harris, of Milton, from 

 whom I have received many interesting species of our more north- 

 ern regions. At first view it might be mistaken for the P. vutnji- 

 nata, Nob., but it is quadruple the size, and the labrum is not 

 reflected and thickened. (Say.) 



Pupa placida, Say, New Harmony Diss, II, 230 (1829) ; Descr. 

 24 (1840); Binney's ed. 39.— W. G. Bunney, Terr. Moil. 

 IV, 145 



Pupa fallax, DfKay, N. Y. Moll. 51.— Gould, Invert. 192. 



Pupa fallax, 8, Pfeiffer, Mon. Hel.Viv. U, 309. 



Bulimus hordeanus? DeKay, /. c. — Binney, Bost. Proc. I, 105. 



BuUmus obscurus, Gould, Mon. Pupa, p. 17. — Pfeiffer, III, 350, 

 on DeKay's authority. 



Pupa costidata, Mighels, is the same as Ilelix harpa. 

 Pupa exigua, Say, &c., is the same as Cari/chium exiguum. 

 Pupa gouldii, BiNNEY, &c., is the same as Vertigo gouldii. 

 Pupa milium, Gould, is the same as Vertigo milium. 

 Pupa modesta, Say, &o., is the same as Vertigo ovata. 

 Pupa ovata, Gould, &c., is the same as Vertigo ovata. 

 Pupa ovidum, Pfeiffer, is the same as Vertigo ovata. 

 Pupa simplex, Gould, &c., is the same as Vertigo simplex. 



