20 THE NAUTILUS. 



shells collected by Mr. Nelson, not previously detected, added to 

 those before credited to the islands, makes a total of 93, or three- 

 sevenths of the animal forms constituting the Fauna of the group, thus 

 far reported. 



It is not unlikely that insect species were collected by Grayson 

 and Forrer and have been described and perhaps published some- 

 where. Only the mollusks collected by Mr. Fisher came under my 

 notice. ROBT. E. C. STEARNS. 



Los Angeles, OaL, May 11, 1890. 



NEW AMNICOLIDAE FROM FLORIDA. 



BY H. A. PILSBRY. 



During the past decade a number of undescribed species of this 

 family have accumulated in our collections, chiefly gathered by Mr. 

 C. "W. Johnson, Prof. C. E. Beecher and the author. 



Amnicola sanctijohannis n. sp. 



Shell slightly rimate, ovate-turbinate, corneous, somewhat trans- 

 lucent, rather thin. Surface glossy, the growth-lines hardly visible. 

 Spire rather high, conic, the apex rather obtuse. Whorls 4^, rather 

 convex, separated by a moderately impressed suture which is mar- 

 gined below by a conspicuous transparent border (not visible, of 

 course, in opaque dead or incrusled shells.) Aperture ovate, angu- 

 lar above, a little flattened on the parietal side ; peristome a trifle ex- 

 panded and blackish in fully adult shells, acute, continuous, the parietal 

 wall adnate but with distinct edge, often somewhat calloused within. 

 Alt. 3.4, diam. 2.4 mm. ; greatest axis of aperture 1.7 mm.; another 

 specimen measures 3.2, 2.5, 1.7 mm. St. John's river, Florida, at 

 Astor, Lake Co., (type locality), and Silver Spring Run, Marion Co., 

 (Pilsbry & Johnson); AVekiva river (C. E. Beecher.) 



This is a larger species than A, floridana Ffld., and differs in being 

 imperforate, translucent waxen-whitish when taken alive, and in 

 showing a distinct sub-sutural margin like " Hydrobia " monroensis. 

 The aperture is distinctly angular above, not rounded as in adult A. 

 floridana. 



The type series was collected by C. W. Johnson and H. A. Pilsbry, 

 in 1894. Mr. Beecher's specimens from Wekiva river are thinner 

 and bear a delicate ferrous incrustation. 



