Occasional Papers of the Museum of Zoology 13, 



A'crifa tcsscllafa Gmelin. 



The raclula of specimens, from the ])i-eak-water at Puerto 

 Cabello (H, X\', 32), has been discussed in another paper 

 (1. c). 



HELICIXID.E 



Oligyra (Alcadia Sericea) riparia tachirensis, 

 new sul^species 



J'jghteen specimens; Estacion Tachira and La Fria, from 

 leaves of trees and shrubs, and on ground in rich humus (aes- 

 tivating). on mountain sides and in lowland jungle (H. I. bd, 

 35 ; II, bd, 40). This species is usually found nearer the ground 

 than is Hclicina coiicciitrica. 



In the A. X. S. P. is a set (no. 14612) of three, lileached 

 specimens of H. riparia Pfr. (1854). from near Calaniar. Co- 

 lombia (L 10. 75. the type locality). They still show signs of 

 the spiral lines and the i)eculiar indentation of the basal edge 

 of the peristome, and appear to be cjuite closely related to O. 

 scricca ( Drouet, 1859). from Cayenne. Other forms of the 

 latter sj)ecies are O. scricca paracusis ( Pfr., 1859), from Para, 

 Brazil, and O. scricca kuchiii (Pfr.. 1872), from Surinam. 

 However. O. riparia is a larger, more depressed shell, with a 

 tendency towards more definite, spiral lines, and more rapidly 

 enlarging whorls. Fresh specimens, of a brown color form, 

 from Aracataca, Colombia (L 11. 74). a few miles northeast 

 of the tyjie locality (A. X. S. P. no. 46579, Rehn and Ilebard, 

 1920). sliovv- the hairy epidermis of the grou]). 



0. r. tachirensis is very similar to the typical form, bur is 

 usually larger, higher, and with a tendency towards less marked, 

 sp'ral lines. Two. quite distinct, color forms occur: dull chest- 

 nu!: Irown (10 specimens) and jiale lemon yellow (8 speci- 



