164 A MANUAL OF AMERICAN LAND SHELLS. 



It is a species of the Central Province. 



Jaw as usual in the genus. Lingual membrane long and narrow. 

 Teeth 50-1-50, with 16 perfect laterals. Centrals with base of attach- 

 ment slightly longer than wide; inferior lateral angles not much pro- 

 duced, lower margin incurved ; reflection slightly shorter than one-half 

 the base of attachment : tricuspid, the outer cusps short, stout, bearing 

 short, stout cutting points; the median cusp stout, reaching almost to 

 the lower edge of the base of attachment, beyond which projects the 

 cutting point; laterals like the centrals, but asymmetrical, as usual, 

 by the suppression of the inner cusp, with its cutting point and inner 

 lower lateral expansion of the base of attachment. There are 16 per- 

 fect laterals, beyond which are several teeth forming the usual gradual 

 transition to the marginals. These latter are aculeate, the cutting 

 points bearing at or about the center of their lower edge a blunt spur, 

 which is a modified form of the bifurcation of the marginal teeth often 

 found in Limax. The marginal teeth have the usual characteristic 

 arrangement in oblique rows, and the separate teeth, as they pass out- 

 ward, have at first the rapid increase for a short distance, and thence 

 gradual decrease in size, usual in Zonites. 



In the genital system (Terr. Moll., V, Plate XII, Fig. B) there are 

 no accessory organs. The penis sac is as long as the vagina, with a 

 constriction near its commencement, and tapers above to a point, be- 

 low which it receives the vas deferens. The genital bladder is oval, 

 with a very short duct entering the vagina above the penis sac. The 

 arrangement is very nearly that of L. campestris. 



This species is referred to by me as L. IngersoUi in Proc. Ac. Nat. Sc. 

 Phila., 1875, and in Ann. Lye. of N. H. of N. Y., X, 169. 



Limax castaneus is a variety of this species. Jaw as usual ; lingual 

 dentition as in the other form, but diifering in having only 34-1-31 

 teeth, with 12 perfect laterals (Terr. Moll, Y, Plate I, Fig. K). This 

 important difference is such as to warrant the belief that the form may 

 prove a distinct species. Genitalia not examined. Blue River Valley, 

 Colorado. It is described thus by Ingersoll : Small and slender; length 

 less than 1 inch ; color a lively brown, with a darker spot over the 

 shield ; head, tentacles, and eye-stalks blacTi ; bottom of foot white. 



