90 THE NAUTILUS. 



The species seems somewhat intermediate between ToniceHa and 

 Trachydermon, with a leaning toward the former, while it seems to 

 be most nearly related specifically to Tonicella marmoreaof Fabricus. 



EXPLANATION OF PLATE IV. 



Fig. 1. Middle valve, interior, from below ; 2. The same valve 

 from above ; 3. Front valve from above ; 6. The same valve from 

 below ; 4. The tail valve from above ; 5. The same valve from be- 

 low ; owing to the spongy condition of the margin the artist has 

 slightly exaggerated some of the vertical striae so that they are liable 

 to be taken for true notches, the number of which is as stated in the 

 diagnosis above. All the figures are considerably magnified, and to 

 a uniform scale. 



A NEW BRACKISH-WATER SNAIL FROM NEW ENGLAND. 



BY HENRY A. PILSBRY. 



Mr. Owen Bryant collected at Cohasset, Massachusetts, the past 

 summer, specimens of an Amnicoloid snail which appears to be un- 

 described. It was found living in company with Paludestrina minuta 

 (Rissoa minuta of authors) and Odostomia impressa. 



PALUDESTRINA SALSA n. sp. PL III, fig. 10. 



Shell very thin, perforate, oblong-conic, about the shape of Amni- 

 cola lustrica ; corneous-gray or a little greenish ; the. surface having 

 the luster of a dull silk, very finely striatulate, weakly decussated 

 with faint spiral stride. 



Whorls 5-^, moderately convex, with the suture impressed but not 

 so deep as is usual in Amnicola or Paludestrina. Aperture ovate, a 

 little less than half as long as the shell, subvertical. Peristome thin 

 and sharp, a little sinuous, the outer lip being somewhat retracted 

 below its upper insertion ; columellar margin concave, thin ; the inner 

 margin adnate, thin and straightened for a short distance near the 

 upper angle of the aperture. Length 3.1, diam. 2, length of aperture 

 1.5 mm. 



Cohasset, Mass. Cotypes in collections of the A. N. S. Phila. 

 (no. 90445), Boston Society of Natural History, and Owen Bryant. 



Compared with the common P. minuta (Totten), this new species 

 differs in its more broadly conic shape, less deep sutures and larger 



