68 THE FOSSIL ECHINOIDEA 



side of the median line, where it is truncated and slightly reenteringly curved. 

 Actinally the test is slightly concave. The margin is tumid, but less so posteriorly ; and 

 there are projections on it — one at the posterior third, and another close to the trun- 

 cation. The anterior part of the test of the ambitus is on a slightly higher level than 

 the sides ; and there is a corresponding upward slope, posteriorly, starting from the first 

 projection on the margin. The apical part of the test is rather roof-shaped ; and there is 

 a rounded eminence passing from the interporiferous zone of the anterior ambulacrum, 

 over the top of the test, backwards to the transverse slit-like process covering the peri- 

 proct. The test slopes from this long keel, is flatter midway between it and the margin 

 than at the ambitus, and slopes more gently anteriorly than towards the overhanging 

 periproct-ridge. 



The apical system is slightly in front of the centre of the upper part of the test ; 

 and the anterior odd ambulacrum is large, broad, very open anteriorly, and has broad 

 poriferous zones. The line of the inner pores of the poriferous zones is nearly straight, 

 and that of the outer pores a curve ; the interporiferous zone is well developed and 

 broader than one of the poriferous zones. The antero-lateral ambulacra are destroyed, 

 except close to the outer end of one, which is not closed ; but the poriferous zones are 

 closer together than in the anterior odd ambulacrum. The posterior ambulacra do not 

 reach to the line of the periproct-ridge ; but they are too badly preserved to be described. 



The periproct is transverse, is overhung by a projection of the keel, and it is in a 

 broad groove very visible from above, which is slightly hollowed out, and merges by a 

 convex edge into the truncated but slightly reentering margin. The highest part of 

 the test is in rear of the centre, but the abactinal roof is very level. 



On the actinal surface there is a larger ornamentation than on the abactinal, and 

 there are traces of a pitted structure in the median line posteriorly. 



Length of the specimen 1-^^- inch, breadth l-^^, height -j^- inch. 



Locality. There is some doubt whether this form came from the Eanikot series, 

 and it may belong to the Khirthars above. Survey-number G fff •■ 



The list says north-east of Petiani, west of Kotri (not found in place, probably 

 Khirthar group). 



Illustratio7is of the Species in Plate XV. 



Fig. 1. The test, side view : natural size. 



3. The test, from behind : natural size. 



2. The odd ambulacrum, slightly pitted : magnified. 



4. The surface of actinal median line : magnified. 



2. Khynchopygus PTGM^us, sp. nov. Plate XV, Figs. 5, 6. 



This species is much smaller than th'e last, but is of the same general shape except 

 in the absence of the long even abactinal keel ; the test is more convex in front from 

 the ambitus to the apex than in the other form. The actinal surface is concave from 

 side to side, and the truncation posteriorly barely exists. 



