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 diliVrs 

 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 (PI. 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. Icevigatus, 

 however, has a nearer approach to the circular pore of Vitrinizonites. 



The geriitalia are figured on Plate III. Fig. B. The ovary is very large (cn>.) 

 and stout : the genital bladder (</. 6.) is globular on a short, narrow duct: the 

 penis-sac (p. s.) is very long, narrow, cylindrical, receiving the retractor 

 muscle (r.) 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, Icevigatus, inornatus, fuliginosus, and Eugeli. 



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 locality, Bald 

 Mountain, Blount Co., Tennessee, on dividing line with North Carolina. At 

 Washington Co., Tcuncssir, it was found by Dr. Rugel. Mrs. G. Andrews 

 found it on Roan Mountain, in North Carolina (over 6,000 feet), on the divid- 

 VOL. xr. NO. 8. 10 



