MACROCYCLIS. 93 



same. Eye-peduncles slender, foot narrow, twice as long as the diameter of 

 the shell. (See p. 88, Fig. 10.) 



This shell, though frequently seen, does not seem to be so numerous in our 

 forests as some other species. It is peculiar for the elegant, rounded shape of 

 the whorls, as seen on their lower surface. It rarely varies from the common 

 type, and cannot be mistaken for any other Eastern species. The animal is 

 voracious in its appetite, almost always preying upon other species with which 

 it may be kept, and so certainly destroying them that I have been obliged 

 to keep them by themselves. This it effects by inserting its narrow body, 

 which it has the power of elongating and protruding very far from its own 

 shell, into the shells of its victims, and then feeding upon them at its leisure. 

 It burrows in the soil under decaying logs. 



See remarks under M. Vancouver -crisis. 



Jaw crescentic, ends bluntly rounded ; anterior surface striated ; concave 

 margin smooth, with a median projection. (See Vol. I. PI. XII. Fig. XI.) 



Lingual dentition (PI. I. Fig. C) : see above, p. 89, 90. 



Genitalia figured by Leidy in Vol. I. PI. XII. Figs. 9-11. The general 

 arrangement is the same as in M, Vancouverensis, but the epididymis is less 

 developed. 



Macrocyclis Voyaua, NKWCOMB. 



Shell widely umbilicated, depressed, planorboid, thin, translucent, with delicate 

 oblique striae of growth, and fine revolving lines, more developed below, very 

 light horn-color ; spire scarcely elevated ; whorls 5, flattened, Fig. 12. 



rapidly increasing, the last broad, flattened below, falling in 

 front ; umbilicus very large ; aperture very oblique, removed 

 from the axis, irregular truncatedly ovate ; peristome thickened, 

 subreflected, flexuose, strongly depressed above and sinuate, 

 ends approaching, connected with a stout, elevated, brownish, 

 ridge-like callus. Greater diameter 21, lesser 18 mill. ; height, 

 4 mill. 



Helix (Macrocyclis) Voyana, NEWCOMB, Am. Journ. Conch., I. 



Part III. 235, PI. XXV. Fig. 4 (July, 1865). 

 Helix Voyana, PFEIFFER, Mon., V. 247 (1868). 

 Macrocyclis Voyana, TKYON, Am. Journ. Conch., II. 246 (1866). W. G. BIN- 



NEY, L. & Fr.-W. Sh., I. 58, Fig. 98 (1869). 



Canyon Creek, Trinity Co., California, and San Diego are the only localities 

 from which it has thus far been received. It may be said, therefore, to inhabit 

 the whole of the California Region. 



The specimen figured was received from Dr. Newcomb. 



Jaw as in Vancouverensis. 



Lingual membrane (PI. I. Fig. D) : see ante, pp. 89, 90. 



Genitalia not observed, but the species is viciparous. 



