VERTIGO. 215 



Vertigo Bollesiana, MousF. 



Shell minutely perforate, ('vlin<lr"n'aUovate, delicately striate*!, Buhtransluccnt ; 

 ajH'x obtiise; suture well difined ; whorls 4, suhronvex ; aperture suborbicular, 

 somewhat flattened on its outer ed|^e ; with 5 

 tcetli, one pronjinent and rather curved on the pari- ^'K- 120. 



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

 smaller, on the eolumellar maro;in, and two slightly 

 elevated iamelliform teeth within and at the base ; 

 peristome subreflected and thickened. Length, 

 .065 inch ; breadtli, .035 inch. (Morse.) "^^S^ ** 



Isthmia Bollesiana, Mokse, Ann. N. Y. Lye, VII L ^^rti^^ Bollesiana. 



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



Vcrlifio Bollesiana, Mouse, Amer. Nat, L 669, Figs. 63- 64 (1868). — W. G. 



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



Fig. 703 (1870). -^ Tryon, Am. Journ. Conch., III. Pt. 4, p. 308, PI. 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 



^- 121- of dentition with that of Lehmann (PL XIV. 



„-_^c3c=='^ Fig. 53) will prove that this species cannot be 



u^ ^ vi ^ -J ^J identical with P. pygmcEa of Europe, as has 



lineoal membrane of Vertigo BolUsi- , ^ ^ ^ nit r^ t/t / k 



been suggested by Mr. (jwyn Jeiireys (Ann. 



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



Vertigo milium, Gould. 



Vol. in. PI. LXXL 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 bv 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- 



