PLACOSTYLUS DIPLOMORPHA. 115 



Placostyli of the P. hartmani group. The statement of Dr. Hart- 

 man that the anatomy is like that of Partula was evidently not 

 based upon an adequate knowledge of the subject. 1 do not regard 

 the present group as in any true sense intermediate between Partula 

 and Placostylus. 



If Diplomorpha be held to be preoccupied by the prior Diplomor- 

 phus, it may be replaced by Hebridaria. 



Key to Species, 

 a. Length of aperture much exceeding half that of the shell; whorls 



8Mi 



b. A parietal tooth and columellar fold developed. 



layardi, p. 115. 



b l . No parietal tooth or distinct columellar fold. 

 c. Aperture vertical. 



d. Ovate, outer lip hardly expanded, orange-red ; 

 whorls 3|. brazieri, p. 116. 



d l . Obese ; outer lip -well expanded or reflexed ; 

 cuticle lineolate. 



e. Last whorl much dilated ; umbilicus very 



ample. peasei, p. 117. 



e 1 . Last whorl less dilated, umbilicus smaller. 



delatouri, p. 117. 

 c 1 . Aperture oblique ; peristome reflexed ; whorls 4-J. 



coxiana, p. 118. 



a 1 . Length of aperture about half that of the shell, or less ; whorls 5^. 

 b. Strongly plicate at the sutures. ruga, p. 119. 



b l . Not plicate. bernieri, p. 110. 



P. LAYARDI ('Brazier' Hartman). PI. 72, figs. 1-5, 17. 



Shell umbilicate, oval, very solid and strong, dull and lusterless, 

 wanting cuticle, the surface coarsely, irregularly wrinkled in harmony 

 with growth-lines, usually stronger, fold-like below the suture ; 

 white throughout, or yellowish ; orange-tinted or dull brown, deepen 

 ing to purplish or dull red behind the lip. Whorls 3^ to 3 j, the 

 apex small, rather obtuse, earlier 1^ whorls densely and finely 

 sculptured with waved and anastomosing wrinkles ; sutures deeply 

 impressed ; last whorl large, inflated. Aperture ear-shaped, but 

 slightly oblique, and either with the peristome entirely white, or 



