PALLIFERA. 



249 



genital bladder is globular, very large, on a short stout duct, entering the 

 vagina near its base. The penis sac is long, cylindrical, larger towards its 

 apex, where both the retractor muscle and vas deferens enter. In several speci- 

 mens examined, the penis sac appeared somewhat different. It had a large 

 globular bulb at its apex. The vas deferens entered beyond the middle of the 

 length of the sac ; it was greatly swollen before entering the sac, for a distance 

 equalling about one half of the length of the sac. At the commencement of 

 this swelling the retractor muscle was inserted. This form of penis sac is 

 figured in Fig. K. 



The balance of the anatomy of Hemphillia seems to be as in the other slugs. 



PALLIFERA, MORSE. 



Generic characters as in Tebennophorus with the exception of the ribs on the 

 jaw. This is an instance of the arbitrary separation of generally allied species 

 on account of the difference of one single character. This is the more unsatis- 

 factory, because the presence or absence of ribs on the jaw may not prove a 

 reliable generic character. It certainly is not so in Dentellaria (see p. 45). 



Confined to the Northern Interior Regions. 



O 



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

 stout separated ribs, 9 in P. dorsalis (Fig. 147), over 15 in P. Wetherbyi The 

 jaw of the latter is arched, and has a blunt me- 

 dian projection, broken by the ends of the ribs. 

 These last are more irregularly developed also. 



The arrangement of the teeth on the mem- 

 brane in P. dorsalis is as usual in the Helicea, 

 See Fig. 148. Separate teeth of the same spe- 

 cies are more correctly drawn on PI. V. Fig. L. 



Mr. Morse gives 115 rows of 56156 teeth each, with perfect laterals. In 

 the specimen examined by me I found 29129 teeth, with 14 perfect lat- 



Fijr. 14R. 



Fig. 147. 



Jaw of P. dorsalis. 



Lingual dentition^of Pallifera dorsalis. 



erals, a difference sufficiently great to raise a doubt of the specific identity of the 

 two specimens. The central teeth have a base of attachment longer than wide, 

 with short lines of reinforcement running parallel to the outer edges at the 



