VERTIGO. 



215 



Vertigo Bollesiana, Mouse. 



Shell minutely perforate, cylindrical-ovate, delicately striated, subtranslucent ; 

 apex obtuse; suture well defined; whorls 4, subconvex; aperture suborbicular, 

 somewhat flattened on its outer edge ; with 5 

 teeth, one prominent and rather curved on the pari- Fi 8- 12 °- 



etal margin, two similar in form, the lower one the 

 smaller, on the columellar margin, and two slightly 

 elevated lamelliform teeth within and at the base ; 

 peristome subreflected and thickened. Length, 

 .065 inch ; breadth, .035 inch. (Morse.) 



Isthmia Bollesiana, Morse, Ann. N. Y. Lye., VIII. Vertigo Bollesiana. 



209, Figs. 4-6 (Nov. 1865). 



Vertigo Bollesiana, Morse, Amer. Nat., I. 669, Figs. 63- 64 (1868). — AV. G. 

 Binney, L. & Fr.-W. Sh., I. 250 (1869). —Gould and Binxky, Inv., 442, 

 Fig. 703 (1870). — Tryox, Am. Jouin. Conch., III. Ft. 4, p. 308, PL XV. Fig. 

 25 (1868). 



New England ; New York ; Virginia. Distribution, therefore, like the last 

 species. 



Animal unobserved. 



Jaw of the same width throughout, slightly rounded at the ends ; cutting 

 edge without projections, finely striated. 



Lingual membrane with 88 rows of (12 — 1 — 12) teeth; base of attachment 

 notched at outer posterior corners ; square, widening posteriorly, armed with 

 three minute denticles, central one largest ; laterals having two minute den- 

 ticles apart, outer denticle nearly obsolete ; marginals scarcely notched. 



A comparison of this description and figure 

 of dentition with that of Lehmann (PL XIV. 

 Fig. 53) will prove that this species cannot be 

 identical with P. pygmcea of Europe, as has 

 been suggested by Mr. Gwyn Jeffreys (Ann. 

 Mag. Nat, Hist., 1872, 246). 



Fig. 121. 



Lingual membrane of Vertigo Bollesi- 

 ana (Morse). 



Vertigo milium, Gould. 

 Vol. III. PL LXXI. Fig. 1. 



Shell very minute, subcylindrical, diminishing equally to both extremities; 

 epidermis dark-amber, or chestnut-color ; whorls 5, rounded, very minutely 

 striated, decreasing slightly to the apex, which is obtuse ; suture deep ; peri- 

 stome white, slightly reflected ; aperture lateral, half the width of the last 

 whorl, within brownish, general shape semicircular, truncated abruptly and 

 directly by the last whorl,a testaceous deposit upon which forms the transverse 

 margin, and connects the two extremities of the peristome ; circumference made 

 up of two curves of different radius uniting in the peristome, where the junc- 



