1903.] NATURAL SCIENCES OF PHILADELPHIA. 781 



Amnicola panamensis Tryon. PI. LII, fig. 11. 



Proc. Acad. Nat. Sci. Phila., 1863, p. 146. 



The type of this species is a single specimen from Panama, collected 

 by Capt. Field, U. S. N. It is of the whitish-corneous color of A. 

 cincinnatiensis Anth., has 4^ whorls which are very convex below the 

 sutures, and the axis is perforate. It is extremely similar to A. cin- 

 cinnatiensis, but differs in being only about half the size of well-grown 

 examples of that species. Length 3.4, diam. 2.7, longest axis of aper- 

 ture 1.8 mm.^ 



An entirely different species collected by Prof. Ralph Tate in Nica- 

 ragua was subsequently referred to A. panamensis, and this erroneous 

 extension of the range of the species has naturally been repeated in 

 the Biologia. 

 Amnicola tryoni n. sp. PI. LII, fig. 10. 



Amnicola panamensis Tryon, Tate, American Journal of Conchology, V, 

 p. 153. 



Shell openly perforate, ovate-conic, thin, corneous and somewhat 

 translucent, the surface smooth, scarcely showing growth striae. Spire 

 conic, the apex slightly obtuse. Whorls 4h, those of the spire very 

 convex below the suture, the last whorl not swollen there. The aper- 

 ture is of the usual ovate contour, svibangular above; peristome adnate 

 to the preceding whorl for a short distance above. Length 2.3, diam. 

 1.6, longest axis of aperture 1.2 nmi. 



Nicaragua, at the roots of plants in a swampy pool near Javali, 

 in the Chontales district, at an elevation of 1750 feet. Types No. 

 58,066, A. N. S. P., collected by Ralph Tate. 



The specimens are encrusted with a ferruginous deposit, so thick as 

 to materially alter the shape of the shell. The one figured has been 

 cleaned. It seems to be closely related to A. guatemalensis Crosse and 

 Fischer,* from Lake Amatitlan; but A. tryoni is a smaller species, with 

 more convex whorls, smoother surface and a more prominent spire. ^1 . 

 guatemalensis is not known to me by specimens. A. stolli JMartens'' 

 seems also to belong to the same group of species, but it is more conic 

 than the others mentioned above, the last whorl being dilated periph- 

 erally, according to Prof, von Martens' figures. 



HELICINID^. 

 Helicina turbinata Wiegm. 



Antigua. State of Vera Cruz. 



' I have every reason to believe this specimen, marked in Tryon's own hand, 

 to be the original type, although it does not agree with the original measure- 

 ments. 



*" Miss. Scient. Mex., Moll., II, p. 264. 



' Biologia Centr. Amer., Moll., p. 645. 



