482 Mr. E. A. Smith on two new bpecies 



Spongodiscus, Zitt. 



Tnronia p. p., Court. 

 Lithosia p. p., Pom. 



Sponge disciform, lenticular, or hemispherical, with a rounded 

 or rounded-hexagonal periphery. Margin acute. One surface 

 (rarely both) slightly convex, the other flat and covered with 

 radiating ribs. Skeletal corpuscles large, quadriradiate, 

 covered with roundish warts, the ends of the arms not 

 branched, but only thickened, or at the utmost slightly 

 forked. The ends are applied to each other ; and thus is 

 formed a wide-meshed skeleton in which the water can circu- 

 late freely. No special canal-system. Isolated large bacillar 

 spicules occur. Tavo species from the Upper Cretaceous : — 



1. Spongodiscus radiatus^ Zitt. 

 Turonia radiata, Court. Ep. xl. 0, 10. 



Disciform. Upper surface with radial ribs and furrows ; 

 under surface slightly convex, smooth. Frequent in flint 

 nodules of Touraine and the neighbourhood of Rouen. Orig. 

 ex. in the museum of Geneva. 



2. Turonia mammiUataj Court, ib. xl. 7, 8. Touraine. 



LIV. — Descriptions of two new Species of Land Sliells from 

 New Granada. By Edgae A. Smith, F.Z.S. 



Cyclotus corpulentus. 



Shell depressed, suborbicular, openly umbilicated, dark 

 olive-brown, lighter or less olive on the upper whorls, and 

 lighter also on the lower surface of the last whorl than on the 

 upper part. Apex generally rather eroded, reddish. Whorls 

 five, very convex, rapidly enlarging, rather coarsely and ob- 

 liquely striated with the lines of growth ; last whorl large 

 and ventricose, almost free from the penultimate at the aper- 

 ture. Suture rather deep, distinctly channelled in front. 

 Aperture very large, subcircular, livid bluish. Peristome 

 simple, pale within at the margin ; columellar side a little ex- 

 panded towards the umbilicus, whitish, joined to the upper 

 or outer margin by a callosity, which is generally broken irre- 

 gularly at the edge, and obliquely nearly rectilinear or but 

 little curved. Operculum almost flat, with only a slight de- 

 pression in the centre, white, thickish, consisting of seven 

 whorls, exclusive of the dark nucleus. Greatest breadth 35 



