North Amerioan Helicidce. 33 



'^^spece dans la Collection de M. de Ferussac, nous I'avions prise 

 pour line variete de VH. aurioulata. Apres I'avoir comparee 

 a cette dernicre, nous lui avons reconnu des caracteres constants, 

 ce qui nous a determine a la conserver conirae espece distincte." 



The annexed figure II. of R. avara Say, double the natural 

 size, is from a specimen collected on the St. John's Fig. II. 

 River, Florida, by Mr. O. M. Dormau. The strice 

 are incorrectly represented, — they should have been 

 shown only at the termination of the last whorl, over 

 a small space immediately behind the peristome. 



a. avara Say may be readily distinguished by its smaller 

 size, more delicate texture, and less globose form, — it has from 

 4 to 4^ whorls, and is the only species of the group which is 

 hirsute. The superior tooth on the labrum is armed with a 

 hook as in the other species, but is narrower, less deeply seated, 

 and more erect ; the inferior one is rather a distinct tooth than 

 a lamellar fold. The parietal process differs entirely from that 

 of II. auriculata, as plainly shown in my figure. II. avara is 

 without the groove on the last whorl which prevails in auriou- 

 lata^ and the forms represented by Dr. Binney as varieties of it. 



The size appears to be constant, — the following are the 

 measurements of the specimen figured : — 



Diara. maj. 7, min. 6, Alt. 3 mill. 



Mr. W. G. Binney (Proc. Phila. Acad., 1857, p. 191), when 

 commenting on the figures of H. auriculata in the Terr. Moll., 

 says : " I do not consider fig. 2, H. avara Say, as a variety of 

 this, but a distinct species. There are some varieties of auri- 

 culata which may be confounded with it, but it is certainly a 

 good species." *I entirely agree in the opinion that fig. 2 repre- 

 sents a good species, but by no means that it is the II. avara Say. 

 Mr. Binjiey mentions having received fine fresh hirsute speci- 

 mens from Mr. Postell, — in this there must be some mistake. 

 The II. avara W. G. Binney from St. Simon's Island and other 

 parts of Georgia, is not hirsute, as Mr. Postell himself assures 

 me, and H. avara Say has not been found there. 



JANUARY, 1858. 3 Ann. Lyo. Nat. Hibt. Vol. VII. 



