76 ABIDA. 



Fauxulus falconianus Pils., Ann. Natal Museum VI, May, 

 1929, p. 299, pi. 20, f. 4, 4a. 



By its attenuate spire this species resembles Fauxulus per- 

 eximius (Melvill and Ponsonby), but that is a far larger shell, 

 said to be 7 ram. long. The figure given by Melvill and 

 Ponsonby is not sufficiently exact to admit of any comparison 

 of the teeth ; if it is to be trusted their species must be quite 

 unlike F. falconianus in the shape of the outer lip. None of 

 the other Fauxuli of the subgenus Anisoloma now known have 

 the spire attenuate as in these species. 



ABIDA (Vol. 24, p. 262). 

 Abida variabilis sillarensis (Piersanti). PI. 18, figs. 5, 6, 7. 



Shell brown or cinereous, alabastrine, elongate, cylindric, 

 not swollen in the middle, the peristome expanded, generally 

 aorthic, sometimes with a white epistomatic callus. 10-13 

 whorls. 



Length 11.2 to 14.3 mm., diam. 2.9 to 3.2 mm. (Piersanti) ; 

 86 per cent of the specimens are from 2.9 to 3 mm. in diameter, 

 and 178 out of 200 are from 11 to 12 mm. long. 



Italy : Appenines of the upper Sillaro valley, Prov. Bologna. 



Pupa variahilis Drap. v. sillarensis Piersanti, Boll, dell'- 

 Istituto Zoologico della R. Univ. di Roma, V, 1927, p. 129-134, 

 figs. 5-7 (fig. 5, variation orthostoma, fig. 6, variation plagio- 

 stoma, p. 134). 



A less convex, more cylindric shell than A. variahilis, differ- 

 ing also from the cylindric A. v. polita, and a descendant of 

 var. producta, found by Strobel on the Tidone and the Secchia 

 ( northwestward ) . 



The locality of this race is a wind-beaten treeless terrace 

 with southern exposure, at an elevation of about 400 meters, 

 having scant vegetation of Artemesia, broom etc., reached by 

 a mule trail which ascends from a spring of sulphur water 

 on the left bank of the upper Sillaro. There is a fauna of 

 mullusks numerous in individuals but few in species, among 

 them this race of Abida variahilis. It lives in families of 20 

 or 30 individuals on small di-y bushes or broom. Even when 



