MUSEUM OF COMPARATIVE ZOOLOGY. 145 
above the margin of the foot, meeting over a round caudal mucus-pore : dis- 
tinct locomotive disk to foot: external orifice of combined generative organs 
on right side of body, far behind the eye-peduncles: of respiratory and ex- 
cretory organs on the right of the mantle under the peristome : jaw smooth, 
with median projection : lingual membrane as in Zonites, central teeth tricus- 
pid, lateral teeth bicuspid, marginals aculeate. 
Shell external, Vitrina-like. 
The above generic name is proposed for the shell described as Vitrina latissima 
(p. 136), as it combines the characters of Vitrina and Zonites. The animal differs 
from Vitrina by having simple, not bifid, marginal teeth to the lingual mem- 
brane, and by a caudal mucus-pore, with longitudinal furrows above the margin 
of the foot, and by the want of an appendiculate mantle. From Zonites it 
differs only in the form of the shell, though the caudal mucus-pore seems to be 
circular, with projecting process when open, rather than a simple longitudinal 
slit, as in Zonites suppressus. There appears no developed appendiculate mantle 
process. 
The genus in my arrangement will follow Zonites. 
Vitrinizonites latissimus, Lewis. (p. 136.) 
Plate I. Fig. H. Plate III. Fig. A, B. 
I here add a figure of the animal in motion (Pl. III. Fig. A), not fully 
extended, drawn by Miss Emma Pringle. The caudal mucus-pore is circular, 
bordered with a narrow transversely grooved rim; and when closed is covered 
completely. When open the cover is raised along its longitudinal centre into 
a sharp carina, leaving posteriorly, when seen from behind, an erect triangular 
opening. It thus differs from the simple longitudinal slit found in most of the 
American species of Zonites, such as friabilis, capnodes, fuliginosus, inornatus, 
demissus, ligerus, suppressus, the last figured in Vol. V., Fig. 47. Z. levigatus, 
however, has a nearer approach to the circular pore of Vitrinizonites. 
_ The genitalia are figured on Plate III. Fig. B. The ovary is very large (ov.) 
and stout : the genital bladder (g. b.) is globular on a short, narrow duct: the 
penis-sac (p. s.) is very long, narrow, cylindrical, receiving the retractor 
muscle (7.) near its basal termination, and merging at its apex into the vas 
deferens*(v. d.). The penis-sac has not the accessory process found in Zonites 
capnodes, friabilis, levigatus, inornatus, fuliginosus, and Rugeli. 
The species has been found from Carter Co. to Blount Co., Tennessee, on 
the dividing line between Tennessee and North Carolina. 
On Roan Mountain it is usually found under damp moss. 
I am indebted to Miss Annie E. Law for the opportunity of examining the 
specimen figured. She collected it in June, 1879, at the original lovality, Bald 
Mountain, Blount Co., Tennessee, on dividing line with North Carolina. At 
Washington Co., Tennessee, it was found by Dr. Rugel. Mrs. G. Andrews 
fourld it on Roan Mountain, in North Carolina (over 6,000 feet), on the divid- 
VoL Xx1I.—wo. 8. 10 
