294 



ME. GUY C. EOBSON ON MOLLIJSCA 



The shell (PL XXXIII. fig. 7 a, h, c) is small and semi-transparent. The apex is 

 decorticated and bleached to a bluish white, while the rest of the whorls are light 

 brown above, slightly tinted with green, and a very delicate dark green below. The 

 whorls number four ; the last increases rapidly in size, while the apical ones are 

 tolerably prominent and convex in profile. The suture of the last whorl is impressed. 

 The aperture is rounded, large, simple, and nacreous within. The umbilicus is shallow, 

 and nearly entirely covered over by a reflexion of the columella. The latter is well 

 rounded. 



Text-figure 8. 



phfh. 



Central nervous system in Chronos suhlimis. eg., cerebral ganglion ; pig., pallial ganglion ; pdg., pedal ganglion ; 

 hg., buccal ganglion; he, cerebro-buccal commissure ; jsAji., pharyngeal nerves; pn., pallial nerve; 

 pdn., pedal nerves. 



The surface is covered by a rather glossy periostracum, marked transversely by 

 irregular growth-lines and fine striae, the former occasioning a kind of irregular 

 transverse striping. The periostracum of the body-whorl is, in addition, seamed 

 by longitudinal grooves, which impart a wrinkled texture to the surface. 



On the apical whorls the transverse sculpture is visible as more regularly arranged 



