CHONDRIN^ OF THE PYRENEAN CENTER. 35 



By the form and the much developed lip it groups with the 

 smaller forms of megacheilos, but differs by the base of the 

 neck not compressed, and by having only 2 palatal plica, as 

 well as by the upper anterior fold [angular lamella] which 

 never penetrates inward to the inner end of the parietal 

 lamella, but always terminates at its forward end (Rossm.). 



The outer lip expands very little or not at all, but the whole 

 peristome is widened by the conspicuous thickening of the 

 inner edge. There is also a wide buff band behind the lip. 

 Typically the teeth are strongly developed, but in one lot 

 labeled Catalonia they are much reduced, low and weak, 

 length 7.9, diam. 2.9 mm., 8 whorls. However, this lot is per- 

 haps not really referable to arigonis. 



In another set from the type locality, the shell is more 

 conic, and there are very minute, deeply immersed supra- 

 palatal and basal plicae (figs. 17, 18, length 6, diam. 2.7 mm.). 

 The surface, in all specimens seen, is nearly smooth or has 

 very low, coarse wrinkles. 



Other described forms of the series follow ; none of them 

 have been figured, and their relations with the better known 

 species remain to be indicated. 



15. CHONDRINA BAREGIENSIS ('Bgt.' Loc.). Cylindric, a 

 little ventricose, 8 slightly convex whorls, the suture well 

 marked ; aperture subtriangular, a little contracted, angular 

 at the base ; 2 small superior folds, the lower well immersed ; 

 1 columellar at the superior angle ; 4 narrow palatals, the 

 upper obsolete, not reaching to the peristome ; peristome thin, 

 very little reflected, sharp ; shell a little shining, dark red, 

 ornamented with coarse stride. Length 9, diam. 3 mm. En- 

 virons of Bareges (Hautes-Pyrenees). (Pupa baregiensis 

 Bourguignat in coll., Locard, Ann. Soc. d'Agric. Lyon. (7), 

 iii, 1896, p. 187.) 



It appears to be distinguished by the single columellar 

 lamella. 



16. CHONDRINA CENTRALIS (Fagot). Quite small, conic, 

 short and squat, rapidly tapering; 7 convex whorls with im- 

 pressed suture. Aperture rounded basally, with parallel mar- 

 gins ; 2 superior folds, one moderate, the other small ; 2 colu- 

 mellars, the lower one more slender; 2 palatals, the lower 

 obsolescent, not reaching the peristome. Peristome acute, 



