NATURAL SCIKNCES OF PHILADELPHIA. 59 



Of Orplinus we have examined one species, B. Hanleyi^ Pfr. 

 (Am. Journ. Conch., VI. 208). The jaw is ribless, with a median 

 projection. The lingnal dentition is given on plate VI., fig. 5. 



Dryptus we have examined in two species, B. pardaiis, ¥6i\ 

 (Am. Journ. Conch., VII. 181) and B. marmoratus, Dunk. (1. c). 

 The jaw of the latter is unknown. In the former it is ribbed. 

 The lingual dentition of B. marmoratus is given on plate VI., fig. 2. 

 In B. pardalis it has not been examined. 



Etirijtus we know from only one species, B. aulacm^tyluH, Pfr. 

 (Ann. Lye. N. II. N. Y., x. 282). The jaw has delicate ribs as in 

 Bulimulus, CylindreMa^ etc. The lingual dentition is given on 

 plate VI., fig. 3. 



A comparison of the figures I have given of the lingual denti- 

 tion of the subgenera of Bulimus shows a greater constancy in 

 that genus than in Helix, especiall}'^ as regards the marginal 

 teeth. 



I add a figure of the dentition of Gochlostyla fvlgetrum, Brod. 

 (plate v., figs. 14-16). See Am. Journ. Conch., VII. 180. 



EXPLANATION OF THE PLATES. 

 Plate II. 



A. Ariolimax NIGER, J. G. Gooper. The tail enlarged to show 



the caudal mucus pore. From the type in the California State 

 Collection, preserved in spirit. 



B. Ariolimax Columbianus? The tail, slightly enlarged, of a 



specimen from Mr. Hemphill (see p. 35) showing the mucus 

 pore. It must be borne in mind that the specimen has long 

 been preserved in spirit. 



C. Ariolimax Columbianus? A specimen from San Mateo Co., 



California, received from Mr. Henry Hemphill (see p. 38). 

 The genitalia about life size. 



1. The testicle. 



2. The epididymis. 



3. The accessory gland of the last ? 



4. The prostate gland. 



5. The sac of the penis. 



6. The retractor muscle of the penis. 

 T. The vas deferens. 



8. The oviduct. 



