358 North American Species of Zonites, etc. 



When first received, I believed this to be an extremely globose 

 form of Z. inomatus, but an examination of the lingual denti- 

 tion showed this to be impossible. 



On pi. XIV, tig. D, I have given a figure of the genitalia. It 

 Avill be seen that the aocassory part of the penis-sac is in this 

 species continued to a point beyond the retractor-muscle : other- 

 wise the genitalia are very similar to those of capnodes, friabilis, 

 inomatus, laevigatas, and fuliginosws. The last species I find 

 to have this accessory process also, though it is not given in 

 Leidy's figure. 



Jaw as usual in the genus. Lingual membrane (pi. XV, tig. I) 

 as usual : teeth 38-1-38. There are about 4 or 5 laterals ; the 

 8th is a pure marginal on either side of the central line. It will 

 be seen in Terr. Moll., V, that inomatus, subplanus and laevigatus 

 are peculiar in having no perfect lateral teeth, but only transition 

 teeth : fuliginosus, capnodes, and friabilis, as well as Rugeli, 

 have well formed laterals, differing in number in' the various 

 species : thus the lingual dentition in this group is a good guide 

 in distinguishing the species. 



The animal is dark slate-colored : the caudal mucus-pore is a 

 longitudinal slit as in suppresstts (see Terr. Moll., V). 



Some individuals have their apicial whorls striate, as in 

 Z. subplanus. 



Zonites plaeentiila, Slmttl. 



On pi. XV, tig. A, I give a figure of what appears to be the 

 true placentula as described by Shuttleworth (whose description 

 is translated in Moll., V, p. 124). The shell there figured, and 

 also figured in this paper, pi. XV, fig. E, is either a distinct 

 species, or an elevated edentate form of lasmodon. 



Zoniies Audrewsi, n. sp. 



On pi. XV, fig. D, is an illustration of a shell lately received 

 from Mrs. G. Andrews, Avho collected it on Eoan Mountain, 

 Mitchell Co., X. C. It has the general appearance of Z. signifi- 

 cans, multidentatus, and lasmodon, but differs so decidedly from 

 each, that I propose to designate it by the name of its discoverer. 

 A full specific description can be given later. Compared with 



