162 Prof. E. Forbes on Fossil Invertehrata from Southern India. 



Oval, gibbous in the centre, with very abrupt sloping sides. The highest part 

 is in the posterior ambulacral space. The posterior extremity slopes rapidly to 

 the margin and includes the long anal groove. The dorsal ambulacra are very 

 regularly lanceolate and stellate. The pairs of pores are connected by grooves, 

 which are not easily seen, either owing to the imperfection of the specimens, or 

 from their having been originally obsolete. The under-surface is very concave. 

 The mouth is rather excentric, and is surrounded by five strong tubercles, between 

 which radiate in star-like fashion five ovate ambulacra. The spinigerous tubercles 

 of the under-surface are very strongly marked. 



2. NucleoUtes {Pygorhynchus) planatus, sp. nov. PI. XIX. fig. 3, a, b, 



N. late ovatus, depressus, vertice centrali, sulco anali oblongo, verticali. 

 Length l^^ inch. Breadth 1/^ inch. Height Oi inch. 



Broadly ovate, rounded at both ends, much depressed, with gradually sloping 

 sides. The highest portion is in the true centre, but from that to the summit of 

 the anal furrow the depression is very slight. The posterior dorsal ambulacra 

 slightly diverge. The anus is placed in a deep, short vertical furrow. The under- 

 surface is very concave. The mouth is excentric and surrounded by five strong 

 tubercles, between which are the broadly-ovate oral ambulacra. The spinigerous 

 tubercles of the under-surface are strongly marked. 



3. NucleoUtes {Cassidulus) elatus, sp. nov. PI. XIX. fig. 1. a,b, c, d. 



N. convexus, turaidus, vertice planato, subcentrali, lateribus abrupte declivis ; infra planus ; 

 anus rotundas, prope marginem posteriorem. 



Length 2i inches. Breadth 2j^^ inches. Height ly% inch. 



Subglobose, flat beneath, very convex above. Summit obliquely depressed, the 

 highest part being behind the centre, sides very steep but sloping. Dorsal ambu- 

 lacra lanceolate. Anus round, impressed, placed above the margin (which is 

 slightly beaked) at about one-third the height of the side. Mouth slightly ex- 

 centric, surrounded by five oblong tubercles which are grooved centrally; between 

 them are the diamond- shaped oral ambulacra, each with an oblong central tubercle 

 separating the series of pores, forming a beautiful star-like arrangement. The 

 spinigerous tubercles of the ventral surface are much developed. 



