DfGEKsoLL.] ZOOLOGY HELICID^. 395 



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

 Teetli 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 alniost to 

 the lower edge of the base of attachment, beyond which projects thei cut- 

 ting-point; laterals like the centrals, but uusymmetrical, as usual, by 

 the suppression of the inner cusp with its cutting- ijoint and inner lower 

 lateral expansion of the base of attachment. There are 16 perfect lateral, 

 beyond which are several teeth, forming the usual gradual transition to 

 the marginals. These latter are aculeate, the cutting-points bearing at 

 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 outward, have at first the 

 usual rapid increase for a short distance, and thence gradual decrease 

 in size. 



A reference to the exhaustive article on the lingual dentition of 

 American Fulmonata, published in the Proceedings of the Philadelphia 

 Academy of Natural Sciences, April 27, 1875, by W. G. Binney, forming 

 part III of volume II of his Conchological Contributions, will show fpages 

 172-177) that this species diflers in its dentition from all the Limaces 

 now known to inhabit ]S"orth America. L. flaims and maximus have no 

 cutting-points to the side-cusps of centrals and laterals. L. Rewstoni has 

 well-developed inner cutting-points to its inner lateral teeth, which in- 

 deed are scarcely distinguishable from the centrals. L. agrestis has also 

 a peculiar inner cutting-point to Its laterals. L. camjjestris has the same 

 type of central and lateral teeth as the species under consideration, but 

 its inner marginals are simple, not bifid. L. Weinlmidi, known only by 

 its dentition, no description of its external characters or genitalia having 

 been published (see Hynemann, Malak. Blatt., X, 212, pi. ii, fig. 1), 

 differs from this species by having all its marginals simple. 



The above comparison of the dentition is given in detail, because it 

 is on its lingual membrane that 1 am forced to relj- for decided specific 

 characters, the external characters of the animal being of little value 

 in alcoholic specimens. 



In the genital system, 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, below which it receives the vas deferens. 

 The genital bladder is oval, with a very short duct entering the vagina 

 above the penis-sac. 



Camp 9 : Hot Sulphur Springs , 1 specimen. 



My notes taken on the spot were lost. The external characters of the 

 animal in alcohol are unreliable ; hence the brief description. 



In Mr. Binney's "Notes" (vol. II, part III, 153), this slug was cata- 

 logued, among the Terrestrial Mollusks of the United States, under the 

 name of Limax ItigersolU, and on pages 174 and 176 of the same work, 

 where the circumstances of its discovery are mentioned, it was referred 

 to as undescribed. In vol. II, part IV, of the same series (now in 

 press), it was described as L. montanus, IngersoU, but the necessity of 

 discarding the former name was not discovered by Mr. Binney in time 

 to make a corresponding change in the designation of the figures, which 

 will bear the name Limax LngersoUi, the plates having already been 

 made. 



