138 BUUMULUS. 



been figured, but the description otters little to differentiate it from 

 pruinosus except the somewhat greater size. 



B. DENDRITIS Morel., vol. x, p. 186, is probably a Drymseus. 



B. VENTANENSIS Pils. Vol. X, p. 189. 



This is evidently close to some forms of B, mendozanus, but it does 

 not seem to be identical, so far as I can tell from the published 

 descriptions. 



B. APODEMETES (Orbigny). Vol. x, p. 187. 



Dr. Borelli collected this species at Tala, prov. Salta, Argentina; 

 San Lorenzo, Prov. Jujuy, and Caiza, in the Chaco, Bolivia (Ancey, 

 Boll. Mus. Zool. ed Anat. Comp. Torino, xii, No. 309, pp. 5, 14). 



B. HELOICUS (Orb.). Vol. x, p. 193. 



The original locality was the Mission de Bibosi, Prov. Santa Cruz 

 de la Sierra. Ancey reports a variety from San Lorenzo, in the 

 Province of Jujuy (Dr. Borelli). He compares it with B. sporadicus 

 (Ancey, 1. c. p. 15). 



The same author states that B. heloicus is abundant around Guale- 

 guaychu, Province of Entre-rios, Argentina (collected by L. De 

 Vries). It is evidently closely related to B. sporadicus, and may 

 only with difficulty be distinguished from some of the varieties of 

 that species. It varies in form, size and color, usually being grayish 

 white with some more or less distinct brown streaks; sometimes it is 

 entirely of a dark reddish-brown color (var. fused). The propor- 

 tions of aperture and spire vary with the shape, which may be more 

 or less swollen; specimens measuring: 



Length 23, diam. 11, length of aperture 12^ mill. 



Length 31, diam. 13, length of aperture 13^ mill. 



Length 25-|, diam. 13|, length of aperture 13 mill. 



The last specimen is the most swollen of all. It has 7^ whorls. 

 The sculpture of the nucleus does not differ from that of B. sporadi- 

 cus. (Ancey, Le Naturaliste, April 1, 1901, p. 82.) 



B. DELUMBIS Reeve. PI. 25, fig. 15. 



Shell perforate, globose-conic, rather solid, rugulose-striate, little 

 shining; white, ornamented with longitudinal chestnut lines inter- 

 rupted somewhat into bands. Spire conic, a little acute. Whorls 6, 



