THE NAUTILUS. 



33 



is large and oblong, upon an extremely short duct. Other organs as 

 usual in Helices. 



No Polygyra or " Mesodon " lias a gland or appendix upon the 

 penis, but in the Mexican genus Praticolella, represented in Texas 

 by P. griseola and P. berlandieriana, a similar structure is found. 

 I do not hesitate to refer jejuna to the genus Praticolella on the evi- 

 dence of this peculiar organ, which has been noticed in no other 

 genus of Helices within our limits. The Floridian snail differs from 

 the Texan and Mexican forms by having an apparently simple penis 

 retractor muscle, while in the other species it is split and has a triple 



Fig. 1. P, penis; p, r, its retractor; a, penial gland ; vd, vas deferens ; ut, 

 uterus ; sp, spernatheca ; vag, vagina. 



insertion on penis and vas deferens. This simple condition was 

 probably the ancestral structure of the genus, since it is that of all 

 other related Helices. 



The shell of this species, which we will now call Praticolella je- 

 juna (Say), agrees somewhat better with that of Praticolella than 

 with any other of our genera of Helices. Not much is known of the 

 habits of the snail. It is quite a local form, which I never happened 

 upon at Miami or elsewhere in some half-dozen visits to Florida. 

 Mr. S. N. Rhoads found it on the " under side of young cabbage 

 palms" at Miami. Further information upon the situations it affects 

 will be of interest In Texas, Praticolella berlandieriana lives on 

 bushes with Bulimulus dealbatus mooreanus, but during prolonged 

 dry weather it burrows in the ground. 



