THE CYOLOPHORID LAND MOIjLUSKS OP AMEiRl'CiA 229 



renders the peritreme complete. The operculum is typically aperos- 

 tomid of about 8 whorls. 



The specimen described and figured, U.N.S.M No. 307422, comes 

 from Cauca, Colombia. It 'has 4.4 whorls and measures : Height, 

 24.7 mm.; greater diameter, 43.8 mm.; lesser diameter, 29.3 mm. 

 Height of aperture, 17.5 mm.; diameter, 20.5 mm. 



There are four additional lots in the National Museum collection : 

 No. 414158, one specimen from Jerico, Antioquia, Colombia. No. 

 424727, two specimens collected by H. Daniel at Jerico, Antioquia. 

 One of these is much larger than the one figured. It has 4.8 whorls 

 and measures. Height, 31.2 mm.; greater diameter, 52 mm.; lesser 

 diameter, 35 mm. Height of aperture, 20 mm. ; diameter, 26.2 mm. 

 No. 307419, one specimen labeled "Colombia." No. 307457, labeled 

 "South America." 



This species belongs to the group that is only feebly malleated on 

 the upper surface. The dark color will distinguish it from A. (A.) 

 veracochanwm^ which is very much thinner-shelled and much paler. 



AFEROSTOMA (APEROSTOMA) VERACOCHANUM, new species 



Plate 31, Figubes 16-18 



Shell very depressed-helicoid, covered with a pale olivaceous-brown 

 periostracum, which on the last part of the last whorl becomes de- 

 cidedly olivaceous both on the upper and lower surfaces. The early 

 denuded whorls are reddish; interior of the aperture bluish white. 

 The nucleus consists of a little more than 2 moderately well-rounded 

 smooth turns; the post-nuclear whorls are moderately rounded and 

 marked by weak retractively curved axial riblets, which find their 

 strongest expression on the first half of the last turn. On the last 

 half, they are enfeebled. Suture strongly impressed, slightly chan- 

 neled on the last part of the last whorl. Periphery very weakly 

 angulated. Base openly umbilicated, strongly rounded, and marked 

 by the continuation of the axial ribs, which on the umbilical wall 

 become much strengthened and fused. Aperture very broadly tear- 

 shaped, with a conspicuously drawn-out angle at the posterior angle, 

 which has a groove in its middle; peristome simple; the outer lip 

 thin; the inner slightly thickened. The parietal wall is covered by 

 a callus which renders the peritreme complete. 



The type, U.S.N.M. No. 524045, was collected by the Wilkes Explor- 

 ing Expedition at Maguas, Peru. It has 4.5 whorls and measures: 

 Height, 24.4 mm.; greater diameter, 43.2 mm.; lesser diameter, 31.5 

 mm. Height of aperture, 16.3 mm, ; diameter, 18.5 mm. 



This species has a much thinner shell and is much paler than 

 A. {A.) cingulatum (Sowerby). 



