198 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 83 



CHONDROPOMETES (CHONDROPOMETES) TORREI Bartsch 



Shell rather large, turbinate, tliin, semitranslucent, openly iimbili- 

 cate, varying in color from pale buff through yellow to orange-buff 

 to brown, unicolor or with a dark vertical band behind the peristome, 

 with or without spiral bands. Peristome expanded and reflected, 

 about half as wide as that of C . {C.) latilabre (d'Orbigny), Nuclear 

 whorls about 2, in perfect conformity in their coiling with the post- 

 nuclear turns. The first is thin, translucent, appearing finely granu- 

 lose under high magnification; the last marked by feeble, somewhat 

 retractively slanting, closely spaced, incremental lines. Postnuclear 

 whorls inflated, well rounded, marked by very regular, retractively 

 slanting, sublamePar axial riblets, which are a little less wide than the 

 spaces that separate them. In addition to these, there are narrow 

 varicial streaks at more or less regular intervals. These may be 

 lighter or darker than the general tone of the shell. They are the 

 result of the approximation of two or more axial riblets. The spiral 

 sculpture consists of quite regularly spaced threads which are sepa- 

 rated by spaces a little wider than the threads. These threads at their 

 junction with the axial ribs render these slightly wavy, and under 

 high magnification give a somewhat serrated aspect to them. The 

 spiral sculpture is very variable in strength, ranging from obsolete 

 to quite pronounced. Suture well impressed ; periphery inflated, well 

 rounded. Base inflated, well rounded, marked like the spire. Axial 

 riblets extend over the wall of the umbilicus, becoming usually a little 

 stronger within. The spiral sculpture within the umbilicus consists 

 of much stronger threads than those on the spire. The last whorl 

 in adult shells is solute for some little distance. The outside of the 

 parietal wall here shows the continuation of the axial riblets. Aper- 

 ture subcircular, slightly angulated at the posterior angle. Oper- 

 culum thin, multispiral, horny, with a fine, granulose, calluslike 

 deposit, which is heaviest on the inner margin and thins out out- 

 wardly, vanishing a little beyond the middle of the turn. This 

 deposit is laid down in more or less of a corrugated pattern. 



The animal of C. (C.) forrei minaenHe has the sides smoky gray. 

 The top of the forehead and back are darker; the tips of the snout 

 are pale bufl' and the tentacles bright orange, slightly paler at the 

 slightly expanded tip, sole of the foot pale smoky gray. Sole of foot 

 medially longitudinally cleft; locomotion of the two sides alternate. 

 When at rest the animal suspends itself by a mucous thread. That of 

 C. (C.) f. collumelare has the dorsal part of the animal smoky gray; 

 sides paler. Sole of foot flesh-color, with a smoky suffusion. Tenta- 

 cles orange-red, Avith the expanded distal portion dark smoKe gray. 

 Snout smoke gray, with the tip flesli-colored with a smoky suffusion. 



