CER1ON, GROUP XIII. 273- 



p. 366, pi. 84, f. 14, 15 ; Monographia, vi, p. 292, SOWERBY, 

 C. Icon., xx, pi. 1, f. 1. 



Pfeiffer's description is given above, and his figures are repro- 

 duced on my plate (figs. 5, 6). 



This differs from other Inaguan species in the simple, small and 1 

 short parietal lamella, often entirely wanting. In the typical form' 

 the color varies from chocolate with white riblets to maculate or 

 nearly white throughout. The ribs extend upon the cone, only the 1 

 first 1^ whorls being smooth, and on the penult, whorl they number 

 as follows : 



Length 21^, diam. 8 mill.; ribs on penult, whorl 24. 



Length 21, diam, 9 mill.; ribs on penult, whorl 29. 



Length 18, diam. 9 mill.; ribs on penult, whorl 31, 



Length 16J, diam. 8 mill.; ribs on penult, whorl 30.- 



Three of these specimens are figured, pi. 46, figs. 7, 8,. 9. The 

 parietal callus, while rather strong and cord-like in some specimens, 

 is quite thin in others, and the ribs are often distinctly seen in the 

 interior. In one tray of 17 specimens, 6 have the parietal lamella 

 more or less developed ; in the others it is completely wanting. 



In another tray of specimens (pi. 46, figs. 13-16) the whorls of the 

 cone are nearly smooth, without riblets, and elegantly marbled, and 

 the form varies from tapering to cylindric; peristome narrow, the 

 aperture dark purplish-brown within. The parietal lamella is either 

 absent (fig. 16), present, small and short (fig. 15), or contiguous to 

 a spiral lamella a half- whorl long, an infra-parietal lamella running 

 parallel to it (figs. 13, 14); these variations occurring among shells 

 of apparently the same age, and agreeing in all other features and 

 variations. 



Var. pudicum Pilsbry, n. v. PI. 46, figs. 17, 18. 



Still other shells exactly reproduce the color-pattern of C. rabi- 

 cundum. The lower two or three whorls are dull purple between 

 white ribs, this ground-color changing above to rose. Riblets on 

 penult, whorl 27 to 31 ; and becoming very fine and low on the cone. 

 The interior is brown or ochre-brown. Parietal lamella rather 

 better developed than in typical bryanti. Of 12 specimens opened,. 

 11 have the simple "Maynardia" parietal lamella, and one has a 

 short accessory denticle beyond it, corresponding to the outer or' 

 spiral lamella of C. rubicundum. 



