204 DRYM.EUS, SOUTH AMERICAN. 



Biilimus yungasensis ORB., Voy. Aruer. Merid., p. 316, pi. 40, f. 

 8. PFR., Monogr., ii, p. 57 ; iii, 345 ; iv, 408 ; vi, 53. REEVE, 

 Conch. Icon., pi. 65, f. 456. 



Some individuals, says Orbigny, entirely lack spots. It is evi- 

 dently near D. zoographiciis, but differs in being perforate and with- 

 out' the columellar twist of that species. Pfeiffer describes a 

 Oumingian specimen apparently from Orbigny, and not in good 

 condition, (fig. 35) as grayish-white with three series of brown spots ; 

 aperture a little shorter than the spire, the last whorl tapering below ; 

 columella subplicate. Alt. 29, diam. 11 mill.; aperture 14?. mill, 

 long, 6 wide. 



D. OCHROCHEILUS (Smith). PL 36, fig. 36. 



Shell ovate-fusiform, narrowly rimate, rather thin, obliquely 

 irregularly striated and malleated ; dull whitish, with series (2 on 

 the upper, 3 on the last whorl) of irregular brown spots. Spire 

 conic, the lateral outlines slightly convex ; whorls 7, slowly in- 

 creasing, a little convex, separated by sutures which are but slightly 

 oblique, the last whorl tapering at base. 



Aperture oblong, narrowly elliptical, half the length of shell, 

 somewhat oblique; peristome rather widely expanded, yellow, the 

 coliiniellar margin reflexed, lips joined by a thin yellowish callus. 

 Alt. 37, diam. 13; aperture 20 mill, long, 5a wide. (Smith'). 



Malacatos, south Ecuador. 



Bidimus (Drymceus) oehrocheilus E. A. SMITH, P. Z. S., 1877, p. 

 362, pi. 39, f. 1. 



This species is closely allied to B. yungasensis of d'Orbigny, and 

 differs from it chiefly with regard to the aperture, which is much 

 longer, narrower and differently colored. Owing to the narrowness 

 of the aperture, the last whorl is also much attenuated, considerably 

 more so than in d'Orbigny's species, which was obtained in Bolivia 

 more than a thousand miles south of where the present form was 

 collected. 



The transverse brown spotting appears rather like interrupted 

 bands than series of spots. These are connected by opaque white 

 lines, and the uppermost series is the narrowest. 



The lines of growth are rather coarse towards the labrum, which 

 shows the yellow color of the interior on the outside. (SmitJi). 



