356 BULLETIN OF THE 



EXPLANATIOX OF THE PLATES. 



Plate I. 



Fig. A, Lingual dentition of Hemitrochus Milleri, Pfr. 



Fig. B. Jaw of same. 



Fig. C. Lingual dentition of Plagioptycha Duclosiana, Fer. 



Fig. D. " " Bulimulus immaculatus ; 6, a marginal tooth. 



Fig. E. " " Leptaxis undata, Lowe. 



Fig. F. " " Bulimulus Schiedeanus, Pfr. 



Fig. G. " " Simpulopsis corrugatus, Guppy. 



Fig. H. " *' Cionella Gloynei, Gibbons. 



Fig. I. " " Zonites Whitneyi, Newc, 



Fig. J. " " Omalonyx felina, Guppy. 



Fig. K. " " Mesodon Chilhoweensis, Lewis. 



Fig. L. *' ** Plebecula lurida, Lowe. 



Fig. M. " " Microphysa Stearnsi, Bl. 



Fig. N. Jaw of same. 



Plate II. 

 Fig. A. Chlamydephorus Gibbonsi. 

 Fig. B. " " lingual dentition. 



Fig. C. Triodopsis vultuosa, Gld., lingual dentition. 

 Fig. D. Urocyclus Kirki, Gray, jaw. 

 Fig. E. " " " lingual dentition. 



Fig. F. Hemphillia glandulosa. 

 Fig. G. Genitalia of Mesodon devia, Gld. ; a, penis sac ; b, genital bladder 



and duct. 

 Fig. H. Vitrinizonites latissimus, Lewis, lingual dentition. 

 Fig. I. Genitalia of Mesodon Sayii, var. Chilhoweensis. 

 Fig. J. Genitalia of Pomatia Buflfoniana, Val, 



0. ovary. 



a. accessory gland. 



e. epididymis. 



ov. oviduct. 



V. d. va.s deferens. 



g. b. genital bladder. 



pr. prostate gland. 



p. 8. penis sac. 



or. external orifice. 



