OF WESTERN SIND. 73 



Ambulacra petaloid, short, subequal, closely approximating at the extremities 

 distally ; poriferous zones equal ; pores equal, round and conjugate. 



Apical disk compact, slightly eccentric in front. 



Peristome pentagonal, more or less eccentric in front, slightly widest laterally ; 

 floscelle well developed, with wall-like bourrelets, 



Periproct suboval, supramarginal, high, overhung by a well-developed supra-anal 

 rostration, with a more or less defined groove beneath. 



Tubercles small, uniform, crowded, equidistantly placed, sunken in deep scrobicules ; 

 slightly larger and more widely spaced on the actinal surface. 



This genus resembles Hhynchopygus to a certain extent in consequence of the over- 

 hanging character of the supra-anal portion of the odd interambulacrum, but differs 

 widely in the great height and posterior eccentricity of the elevation of the test, and 

 is further distinguished by the small and petaloid ambulacral rosette, the equal pores, 

 the comparative simplicity of the floscelle, the absence of a median, pitted, actinal band, 

 and the small and homogeneous character of the actinal tuberculation, which is very 

 slightly larger than that above the ambitus. It differs from Pygorhynchus in the form 

 of the test, the character of the ambulacra, the structure of the floscelle, and the 

 absence of the median band. It is distinguished from Echinanthus by the form of the 

 test, the supra-anal rostration, and the proportions and character of the petals and 

 pores. From Catopygus, to which the form of the test presents a somewhat exagge- 

 rated resemblance, it is well defined by the character of the ambulacra, the concave 

 actinal surface, and the structure of the floscelle. 



1. Paralampas pileus, sp. nov. Plate XV, Figs. 11-14. 



The test is high, longer than broad, broadest posteriorly, very convex above, and 

 rather concave below, except at the tumid margins. The sides of the test are swollen 

 and project outwards more than the margins, and slope up roundly to the top. The 

 gi-eatest height is between the distal ends of the posterior ambulacra ; and thence the 

 test slopes forwards, slightly, to the apical system, which is eccentric and in front, and 

 roundly and sharply backwards to the ridge over the narrow periproct, which is about 

 two thirds of the distance from the margin. The transverse outline of the test above 

 the ambitus is nearly semicircular, but there is a slightly angular summit. At the 

 margin the test is rounded and narrow in front and broadly rounded behind ; and there 

 is a concave surface along the actinal median line. 



The peristome is small, eccentric in front, transverse and pentagonal. There is 

 a projecting ridge or lip from each interambulacral space or bourrelet ; and traces of 

 double pores are seen in one part of this badly preserved portion of the test. 



The apical system is eccentric and slightly in front, and is moderate in size ; the 

 madreporiform body is central ; and there are four generative pores. Near it, the inter- 

 ambulacral spaces are excessively narrow, in consequence of the rather abruptly broad 

 petals of the trivium. The anterior odd ambulacum, the longest, is petaliform, passes 

 along the anterior declivity of the test, does not reach the margin by a distance nearly 



