The Hon. E. Chitty on the Stoastomidse. 71 



Fortunately I happen to be "the correspondent " who found the 

 shell S. pisum in " a Hving state ;" when it is, and continues after, 

 if so taken, of a " sea-green " colour externally. I have also exa- 

 mined the outward form of the animal. The following are my rough 

 original notes made long ago upon it : — 



"Stoastoma pisum. 

 " The animal seems to have but one pair of horns, and is thus 

 shaped. 



[The drawing supposes the animal to be in motion.] 



" Horns short, thick at base, and pointed. Mollusk black, or of 

 the darkest bottle-green. Seems to aid its progress by its snout." 



So different, then, is the animal and shell from either Cyclosto- 

 midcR or Helicinidcc, that with propriety we may take it out of either 

 family and place it as a distinct family, Stoastomid^, Adams, 

 which I divide into the following genera ; adding, however, to Adams' 

 description, " all the species " — "are sculptured with spiral lines ;" 

 this, " except very rarely, as in the instance of S. Philippianum ; " 

 and it is right also to mention, that this family possesses the habit 

 of absorbing part of the internal structure of their shells, as pointed 

 out by Mr. Bland in a paper read before the Lyceum of Nat. Hist. 

 N. Y. (see Annals), Feb. 27th, 1854. 



The genera will stand thus : — 



First, those most singular shells having, as it were, two mouths, 

 such as the only two hitherto known, St. Affassizianum, Ad., and St. 

 Philippianumy Ad., demand a section to themselves. These and two 

 others I shall call Genus Lewisia, in compliment to Prof. L. 

 Agassiz. 



Secondly, those beautiful ones, like St. Gouldianumt with long 

 projecting termination of the last whorl, and such decided sculpture of 

 a few (four or six) strong transverse striae, with fine ones intervening 

 — being all of subdiscoidal form (" Gouldia " being preoccupied 

 among marine shells), I shall call Genus "Wilkinson^a," in honour 

 to the memory of the lady whose name it bears, as well as to that of 

 Adams, it being the second shell of the kind he described : with a 

 subdivision for those devoid of the lengthened last whorl, but with 

 similar sculpture. 



Thirdly, those singular shells with somewhat depressed spire, sub- 



