PALLIFERA. 251 



It is quite possible that this is one of the species described by Rafinesque ; 

 but from the poverty of his descriptions, we are unable to identify it with either 

 of them. 



When Dr. Binney for the first time procured this animal, not being able to 

 distinguish the separation of the margin of the mantle from the edge of the 

 foot, he felt assured that it must be a species of Rafinesque's genus Philomycus, 

 and he accordingly described it as such. Having an opportunity since that 

 time of examining several of them, he noticed, on throwing some of them into 

 alcohol for preservation, that the contraction caused by the liquor revealed 

 and detached the mantle from its adhesion. Its characters, therefore, corre- 

 spond with those of the present genus. 



For jaw and dentition, see above and PI. V. Fig. L. 



Pallifera Wetherbyi. 



From near the mouth of Laurel River, Whitley County, Kentucky, Mr. A. G. 

 Wetherby collected many specimens of what appeared to be a small species 

 of Tebennophorus. It was readily distinguished from the numerous young of 

 T. Caroliniensis found in the vicinity by the arrangement of the blotches of 

 color, they being in irregular, interrupted, transverse bands, instead of running 

 longitudinally as in that species. The anterior portion of the body seemed also 

 to be more swollen, and the posterior extremity to taper more rapidly than in 

 Caroliniensis. On examining the jaw I found it to be ribbed, a character pla- 

 cing the slug in the genus Pallifera. The presence of ribs was verified in four 

 individuals. Small specimens of T. Caroliniensis from the same locality had 

 the usual ribless jaw of Tebennophorus. It appears, therefore, that the slug 

 must be considered a new species of Pallifera. I have named it after its dis- 

 coverer. It is difficult to draw more satisfactory specific characters from speci- 

 mens preserved in alcohol. One of them in its contracted state measures 12 

 millimetres in length. Subsequently, I received specimens in which the blotches 

 run longitudinally. 



Pallifera Wetherbyi, W. G. BINNEY, Ann. Lye. of Nat. Hist, of N. Y., XL 31, 

 PI. II. Fig. 12 (1874). 



Jaw arcuate, ends blunt, but little attenuated; anterior surface with decided, 

 separated, unequal ribs, denticulating either margin, about 15 on one specimen, 

 those at the ends being less developed than on the balance of the jaw ; cutting 

 edge with a decided, short, blunt, median projection. (See plate referred to.) 



The lingual membrane (PI. V. Fig. M) has 35 1 35 teeth, with 13 perfect 

 laterals. The teeth are different from those of P. dorsalis, and nearer those of 

 Tebennophorus Caroliniensis. The side cusps of the centrals and laterals are 

 subobsolete, and have no distinct cutting points; the median cusp is much more 

 produced, stouter, and bears a stout, blunt, cutting point. The marginal teeth 

 are not so wide, they are less irregularly denticulated, having usually one long, 

 stout, blunt, oblique, inner cutting point, and one shorter side cutting point. 



