1901.] NATURAL SCIENCES OF PHILADELPHIA. 477 



The clausilium (PI. XXVII, figs. ^30, 31) is parallel-sided, 

 acumiuate below, abruptly and deeply emargiuate above ou the 

 columellar side of the filament. 



Length 10, diam. 2 mm. 



This specimen agrees with von MollendorfTs description of C 

 grac'dispira in color and form, but differs in having fewer whorls, 

 9i instead of 10-11, and in having two minute intermediate 

 palatal plicae instead of only one. Moreover, the lip is rather 

 broadly reflexed, not merely " hreviter expansum." 



The reddish specimen (PI. XXVII, figs. 32-34) is wider than 

 the green, with the space above the principal plica very convex 

 (fig. 34). Whorls 9^. The aperture is less oblique than in the 

 green specimen, but otherwise similar; the oblique flattening of 

 the top of the superior lamella, and the notch in the pei'istome to 

 the right of it being well marked. Internally it is similar to the 

 green specimen except in the following respects: the spiral and 

 inferior lamellpe are longer, ascending almost j)ast the ventral 

 position; and between the upper and lower palatal plicre there is 

 one very low, nodule-like callus or intermediate plica. 



Length 10, diam. 2.2 mm. 



This specimen agrees with von Mollendorff's description in 

 having an identical palatal armature. In color and general 

 appearance it is a good deal like C. atirantiaca var. Erberi Bttg. 

 I did not examine the clausilium. The rather peculiar form of 

 the superior lamella, in a front view, is the same in the two speci- 

 mens; and when the intermediate palatal plicfe are so reduced as 

 in these shells, I am disposed to beheve that the differences above 

 recorded are not of specific value. 



It is obvious, however, that more material is needed to satisfac- 

 torily elucidate the characters of the species. 



Groiqj of C. sublunellata. 



This group was defined by von Mollendorft' in 1885. It js 

 characterized by the palatal armature, the species examined by 

 him having " below the principal plait, first an upper palatal, after 

 this a very short second one, and then a short, straight lunella, 

 which in some forms is somewhat obsolete, but always discernible." 



In my opinion the group should be enlarged to include species 

 which have below the principal plica or jilait, one upper palatal 



