STROPHOCHEILUS-BORUS. 27 



straightened, slightly receding, white. Aperture subvertical, sinu- 

 ate-oval ; peristome thickened, narrowly expanded, whitish, the 

 right margin somewhat straightened, with a tubercular thickening 

 inside. Length 100, diam. 48 mill.; apert. measured inside, alt. 4u, 

 diam. 20 mill. (Pfr.). 



Baliia, Brazil (Sowb.). 



Bulinus auritns SOWERBY, Conch. Illustr. f. 76. Bulimus auritns 

 PFR., Monogr. ii, p. 25; iii, 304; iv, 366; vi, 11. B. ovatus white- 

 lip dwarf var., REEVE, Conch. Icon. pi. 89, f. 2126. 



Evidently belongs to the ovatus group, but differs from that species 

 in the smaller mouth and white lip, the columellar reflexion not con- 

 tinuing so far downward, etc. The strongly developed tubercle with- 

 in the outer lip is characteristic. 



I refer to this species a pair of solid, heavy shells before me 

 collected by Anthony on Agassiz's expedition to Brazil, one of 

 which is figured on pi. 16, fig. 26. Traces only of a yellow, streaked 

 cuticle remain. The aperture is under half the shell's length, wide 

 and truncate below ; outer lip with a median somewhat lobed callous 

 tooth ; columella with a lump above. Alt. 84, diam. 50 mill. ; alt. 

 of aperture 40 mill. 



S. OOSOMUS Pilsbry, n. sp. PI. 18, figs. 32, 33. 



Shell short-oval, globose, solid and strong, with thin straw-yellow 

 cuticle having occasional narrow brown streaks, the shell-substance 

 under it white toward the base, reddish-brown above, with a wide whit- 

 ish sutural band. Spire short; sutures deeply impressed, the last 

 one oblique, the surface below it somewhat " puckered "or wrinkled 

 as in B. ovatus. Whorls 5J, the first planorboid, smooth, white, the 

 second having strong curved radial ribs separated by intervals of 

 about their own width ; and about the middle of the third whorl 

 these ribs become more spaced and shorter, not extending to the 

 suture below ; the surface at the same time becoming densely gran- 

 ulated spirally. Post-nepionic whorls If, at first finely wrinkle- 

 striate and densely granulated. Surface of body-whorl finely malle- 

 ated in obscure diamond-pattern, and covered with a minute sparse 

 and irregular granulation. 



Aperture narrow-ovate, subvertical, bluish-white within ; per- 

 istome white, hardly expanded, but considerably (3 mill.) thickened 

 on the face and within ; outer lip evenly arched ; columella arched 

 below, oblique above, reflexed and appressed over the umbilical 



