CRYPTAZECA. 283 



boscidiform, grooved above. Posterior end abruptly, strongly 

 truncate, the truncation with a pit, the outlet of mucous glands; 

 beyond this it terminates in a rather long tail. Pedal disk 

 thick, separated from the body by a deep longitudinal furrow 

 which defines a pedal margin one-third the height of the body; 

 margin transversely sulcate, and crenulated by the sulci below. 

 Two feeble longitudinal grooves divide the flanks into three 

 reticulated zones. The mantle extends over the parietal callus. 

 The movements of the animal are very lively. 



Type, C. monodonta. 



This peculiar form of the Basque country is isolated among 

 continental groups. It is more closely related to those of 

 Madeira. Cryptazeca may well be a relict form of the Iberian 

 early tertiary islands, and genetically connected with the 

 Madeiran groups. Anatomically it resembles Ferussacia, the 

 jaw and radula being similar, but the mantle is apparently not 

 reflexed over the outer lip of the shell around the aperture, as 

 it is to a greater or less extent in Ferussacia. 



By its abruptly truncate columella, Cryptazeca differs from 

 Ferussacia proper, but the same feature occurs in some Madeiran 

 species, in Calaxis, and in Azeca. 



C. MONODONTA (de Folin et Berillon). PL 48, fig. 22. 



Shell minute, subelliptical, wider below; apex obtuse; longi- 

 tudinally very minutely and regularly striate, translucent, 

 glossy, pale fulvous. Whorls 5 or 6, slowly increasing, nearly 

 flat, slightly convex, joined by a linear, hardly impressed 

 suture; the last whorl larger, two-thirds the total length. 

 Aperture long, subpiriform, narrow above; outer lip arcuate, 

 arched forward and slightly bent inward below, with a feeble 

 callus or thickening most pronounced at the inflection; it is 

 reddish-brown. Columellar margin separating into three lines 

 below: the lower line running out in a rather prominent tooth, 

 the intermediate line following the columella and disappearing 

 above, the outer line curving gracefully, continuing the peri- 

 stome across the parietal wall. Length 4, diam. 1.6 mm. 

 (Folin). 



S. W. France: Basses Pyrenees, near Cam bo, on the bank of 



