DRYM^US, SOUTH AMERICAN. 223 



Aperture large, a little exceeding half the length of the shell, 

 vertical, more or less deeply lilac colored and showing the external 

 markings within ; peristome very broadly expanded throughout ; col- 

 wnella strongly twisted, obliquely truncate below, its margin very 

 broadly, flatly dilated above, making an angle with body whorl at 

 the insertion. 



Alt. 42, diam. 22 ; alt. of aperture 23 mill. 



Alt. 44, diam. 20 ; alt. of aperture 24 mill. 



Upper Amazon drainage in eastern Peru : Huallaga (Sowb.) ; 

 Moyobamba (Yates) ; Pebas (Castelnau) ; Huancavelica (Castelnau) ; 

 between Lamas and Tarapoto (Phil., for B. auris-ratti). Also, Cane- 

 los, Ecuador (Almagro). 



Bulinus pulchellus SOWB., Conch. Illustr., f. 91. Not Bulimus 

 pulchellus Brod., P. Z. S., 1832, p. 106. Bulimus expansus PFR., 

 Monogr., ii, p. 60 ; iii, p. 331 ; iv, p. 394 ; vi, p. 40. HIDALGO, Journ. 

 de Conch., 1870, p. 47; Viaje al Pacifico, p. 71. HUPE in Castel- 

 nau, Anim. Nouv. ou rares Amer. du Sud, p. 42, pi. 6, f. 3. CROSSE, 

 Journ. de Conch., 1871, p. 316. Bulimus iodostomus DEVILLE & 

 HUPE, Revue Zool., 1850, p. 641, pi. 15, f. 2. Otostomus pulchellus 

 DOHRN, Jahrb. D. M. Ges., ix, 1882, p. 106. Bulimu* auris-ratti 

 PHIL., Malak. Bl., xiv, 1867, p. 69. PFR., Novit. Conch., p. 336, pi. 

 80, f. 10,11. 



The strong rib striation, short, full body-whorl, twisted columella 

 and conspicuously expanded peristome are characteristic. The lilac 

 or purple color of the aperture varies to a faint tint in some speci- 

 mens ; and the external markings are quite variable. 



Dohrn mentions a short variety, alt. 33, diam. 25 mill. ; and a 

 specimen in Pfeiffer's collection is long and slender, alt. 30, diam. 

 17 mill. The broader examples have a sort of perforation at the 

 end of the umbilical chink, but this is closed in the more slender 

 shells. 



Philippi's B. auris-ratti (pi. 34, figs. 3, 4) is referred to expansus 

 as a synonym, by Dohrn. The figures show a more straightly conic 

 spire with less convex whorls, but this may be a fault of the draw- 

 ing. It comes from the region inhabited by D. expansus. 



Var. VANATTAI n. v. PI. 34, fig. 6. 



Smaller than typical D. expansus ; cream or brownish, becoming 

 flesh-pink above, with longitudinal purple-brown maculae and two 

 more or less interrupted spiral girdles ; sculpture of white, thread- 



