356 North American Species of Zonites, etc. 
cannot judge of the character of the tail from the alcohol 
specimens received. 
The jaw is low, wide, shghtly arcuate, ends blunt and but 
little attenuated ; cutting edge without median projection. 
Lingual membrane long: teeth, 23-1-23, the transverse rows 
arranged en chevron : centrals small, tricuspid : no lateral teeth : 
all the side teeth are aculeate marginals (Pl. XV, fig. K). 
Maerocyclis Hemphilli, n. sp. 
At Olympia, Oregon, Mr. H. Hemphill collected several speci- 
mens of a Macrocyclis (pl. XV, fig. M), which appears to be dis- 
tinct from, though nearly allied to, W. Vancowverensis. It may 
be best described by saying that— 
The umbilicus is narrower and not excavated so much—the termination 
of the last whorl not receding from the umbilicus as in all the forms of 
Vancouverensis and concava—in all, the whorls are more or less strongly 
striated within the umbilicus—often almost ribbed in concava ; not so in this 
shell—the texture of the shell is glassy like Hyalina, and there is no 
trace of the microscopic spiral lines found in all the other forms ;—beneath, 
the last whorl is proportionately wider. The greater diameter is 14 mill. ; 
lesser, 10 ; height, 5. 
The jaw and lingual dentition are as usual in the genus (See Terr. Moll. 
of U.§., vol. V, p. 88). I could not distinguish the characters of the cen- 
tral tooth in this species. 
Vitrinizonites lAtissimuUs, Lewis. 
I have already, in the Bulletin of the Museum of Comparative 
Zoology, vol. V, No. 16, p. 3833, given a description of this genus 
and a figure of its lingual dentition. I here add a figure of the 
animal in motion (pl. XIV, fig. A), not fully extended. The caudal 
mucus-pore is circular, bordered with a narrow transversely 
erooved 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, tnornatus, demissus, ligerus, 
suppressus, the last figured in Terr. Moll., V, fig. 47. 2. laevi- 
gatus, however, has a nearer approach to the circular pore of 
Vitrinizonites. 3 
The lingual dentition (see Bull. Mus. C. Zool., 1. c.) is nearer 
; 
: 
