CONCHYUA—DITHYRA. xxv 



19. Kellia. 



1. suborbicularis, subrotunda, cequilateralis, alba. 



roundish, equilateral, and white. 



2. rubra, ovata, ineequilateralis, rubra. 



oval, inequilateral, and red. 



20. MONTACUTA. 



1. substriata, costulis longitudinalibus obscurisl 



with obscure longitudinal ribs. 



2. bidentata, dente altera obliquo cochleariformi. 



one of the teeth oblique and spoon-shaped. 



3. ferruginosa, dente altera inflexa concave. 



one of the teeth inflected and concave. 



4. oblonga, dentibus erectis. 



with all the teeth erect. 



21. Lepton. 



1. squamosum, squamoso-punctatum. 



punctured in a scale-like manner. 



2. nitidum, substriatum tiitidmn. 



slightly striate and glossy. 



22. LUTRARIA. 



1 . oblonga, latere antico truncata. 



truncate at the anterior end. 

 • c 



