216 AMERICAN PSEUDOPEAS. 



23. 0. ADAMSI n. sp. PI. 50, fig. 18. 



Shell minutely perforate, subcylindric, thin but moderately 

 strong, milky-corneous, somewhat translucent. Surface sculp- 

 tured with excessively fine, close stride, which are slightly arcu- 

 ate and a little oblique. Whorls 8%, quite convex, the later 

 ones a little flattened in the middle; suture very deeply im- 

 pressed. Base of the last whorl very convex. Aperture 

 slightly oblique, small, rhombic-ovate. Outer lip arched for- 

 ward a little above. Oolumella slightly concave, dilated above. 

 Length 8.9, diam. 2, length of aperture 2 mm. 



Panama (C. B. Adams). Type in coll. Amherst College. 



This very slender and narrow species is related to 0. coli- 

 mense, which is larger, more tapering and more coarsely 

 striatulate. It is named in honor of Professor C. B. Adams. 



Genus PSEUDOPEAS Putz. 



See p. 114. The following species has the embryonic shell- 

 sculpture and viviparous reproduction of this African genus. 



P. VIVIPARUM (Miller). PI. 29, fig. 81. 



"Shell rimate, thin, glossy, diaphanous, fulvous, ribbed; 

 spire turrite, the apex rounded; whorls 5%, convex the first 

 minutely decussate, very rapidly increasing, the following 

 whorls ribbed, the ribs acute, arcuate, sometimes split, the 

 intervals flat, twice the width of the ribs; last whorl flat- 

 tened at the periphery, not half the total length. Colu- 

 mella straightened. Aperture acuminate-oval, not oblique; 

 peristome simple, acute, receding above, the columellar mar- 

 gin angularly reflexed, dilated, adnate above; margins sub- 

 parallel, joined by a parietal callus. Length 6, diam. 3, aper- 

 ture 2.5 x 1.5 mm." (Mill.}. 



Ecuador: Val de Pilaton, over 1000 meters above the sea, 

 on leaves (Boetzkes). 



Opeas viviparum MILLER, Malak. Blatter xxv, 1878, p. 

 197 ; and neue Folge i, 1879, pi. 6, fig. 4. 



The single specimen examined by Miller contained the 

 viscera, in which two embryo shells were found. They con- 

 sist of 1.1/2 whorls, with very delicate, close spiral striation. 



