226 TEBENNOPHORID^E. 



FAMILY TEBENNOPHORID^E. 



Animal naked, slug-like. Mantle covering the entire back. 

 No mucous pore. No distinct locomotive disk. Jaw oxygnath- 

 ous. Lingual dentition similar to Helix. No internal shell. 



Genus TEBENNOPHORUS, Binney, 1842. 



Animal limaciform, convex, compressed, slightly attenuated 

 behind, obtuse anteriorly ; mantle vermiculated, covering the 

 entire dorsal surface of the body, with the pulmonary orifice on 

 the right margin and anterior, close to the head ; foot separated 

 from the mantle by a groove. Jaw (PL 44, fig. 7) longitudinally 

 striated, with a median projection. Lingual membrane (PI. 44, 

 fig. 6) long and narrow, central tooth triangular, the lateral cusps 

 obsolete, outer laterals bicuspid, marginals quadrangular, obtusely 



bicuspid. 



Eastern North America. 



Dr. Gray has described a rudimentary nail-like internal shell, 

 but subsequent authors have not observed any shell. 



A number of authors have preferred the generic name Philo- 

 mycus, Rafinesque, 1820, a genus distinguished, like his Eumelus, 

 by the absence of a mantle. Like others of Rafinesque's groups, 

 it may have been imaginary at any rate there is no means of 

 identifying it positively with the present group, and I therefore 

 adopt the oldest name accompanied by a good diagnosis. 



Section MEGHIMATIUM, Van Hasselt, 1824. 

 (Incillaria, Benson, 1842.) 



Body convexly depressed, mantle smooth. Other characters 

 as in Tebennophorus. Asiatic. 



The two groups are better distinguished by their widely sepa- 

 rated distribution than by the flatness or convexity of the body, 

 which appears to be the only structural difference. If united, 

 Meghimatium, which has priority, should be retained as a syno- 

 nym, because it was not sufficiently defined. See " Ueber die 

 Anatomic der Gattungen Incillaria Benson und Meghimatium 



