204 



slightly angulated; spire obtuse; columella straight, 

 continued below the base- of the right side, occasioning 

 an angle to be formed at the lower part of the aperture ; 

 a sinus in the margin of the outer lip, which, from the 

 delicate substance of the shell, is seldom seen perfect. 

 These shells are found floating on the surface of the sea, 

 suspended by a vesicular appendage, attached to the 

 foot of the animal, which emits a violet-colored liquid, 

 when touched. Two species are described by La- 

 marck; but Sowerby mentions two others, the J. glo- 

 bosa, and a species found upon our own coasts, though 

 very rarely: and among many unique and non-descript 

 shells in the late Earl of Tankerville's cabinet, the 

 writer has observed another very distinct and beauti- 

 ful species. 



Janthina communis Janthina exigua. 



;:■■• 



k 



SIGARETUS. 



Ill 1 1\ IIALIOTOIDEA. LlUH. 



Mart. 1, table l6,fiff. 151, 154. 



The Sigaretus is a shell concealed in the mantle of the 

 animal producing it. Jt somewhat approximates the 

 G. Natica, greatly resembling a very depressed shell 



