North, American Helicidce. 37 



In the description in French, the shell is said to have 4^ 

 whorls, and to be 4 or 5 mill, in diam. As to the umbilicus, I 

 extract the following passage : — 



" Le dernier tour est convex en dessous ; un omhilic etroit est ouvert 

 a son centre, et cet ombilic est en partie cache par I'extremite du bord 

 droit qui s'implante et se dilate sur son pourtour." 



Pfeiffer in Mon. I. describes this species as '■^ subobtecte perfo- 

 rata,^^ and gives as measurements — " diam. maj. 6, min. 5^, 

 alt. 3 mill." In Mon. III. he has the following, as variety of 

 H. pustula, — 



/3. ^lYosa, umbilico fere omnino obtecto. (Mus. Cuming. spec, autbent.) 

 H. leporina Gould in Proc. Bost. Soc. 1848, p. 39, 

 " " Reeve Conch. Ic. No. 722, t. 121. 



I suspect that Pfeiffer's description in vol. I. rather refers to H. 

 leporina. In Yol. HI. Pfeiffer suggests that II. Zecontii Lea 

 may be an umbilicate variety of H. pustula, — it is identical with 

 H. loricata Gould. 



The magnified figure (fig. 20) in Chem. ed. 2, is quite unin- 

 telligible. 



Dr. Binney in Terr. Moll, describes as H. pustula Per. a shell 

 which I believe to be entirely distinct. He says of it, — " the 

 spire is flat, has five closely revolving, rounded whorls, sepa- 

 rated by a deep suture, the outermost obtusely angular at its 

 upper limit ; beneath convexly rounded into a large umbilicus, 

 one-third the breadth of the base, and exhibiting the other 

 whorls within, and with a constriction behind the lip." He men- 

 tions that it is found at Darien, and Lee county, Georgia, and 

 in Florida. In his " Remarks" Dr. Binney speaks of the umbi- 

 lical perforation as being " far broader than in any other of the 

 polygyral group." 



Comparing the two descriptions above quoted, I was for some 

 time at a loss to understand Dr. Binney's species. 



