MOSS & WEBB : ANATOMr OF TEACHXCYSTIS, ETC. 



265 



3. ISOMERIA ST7BCASTANEA, Pfr. 



The specimens upon wliich the following investigations were made 

 were kindly given by Mr. S. I. Da Costa, and came from Ecuador. 

 Isomeria is placed under Pleurodonte ^ in Pilsbry's classification, but up 

 to the present nothing has been described save the shell. 



III. VII. 



Fig. I. Genitalia of Trachycystis lygcea, Melv. & Pons., from "West Africa, 



enlarged three times. 

 ,, II. A median tooth with the two adjacent laterals and a marginal one 



from tho radula of the same, enlarged. 

 ,, III. The jaw of the same, enlarged. 

 ,, IV. Genitalia of Dorcasia globulus, Miill., from Eobbin Island, slightly 



reduced. 

 ,, V. Genitalia of Isomeria sicbcastanea, Pfr., from Ecuador, somewhat 



reduced. 

 ,, Ya. The Junction of the epiphallus and penis in a second specimen. 

 ,, VI. A median tooth with the two adjacent laterals and a marginal one from 



the radula of the same, enlarged. 

 ,, VII. The jaw of the same, enlarged. 



1 T.e., p. 93. 



