OF WESTERN SIND. 11 



the petal. In the anterior lateral petals the posterior zone is slightly curved outward, 

 whilst the anterior one is straight. 



The poriferous zones are narrow and of uniform breadth throughout, excepting 

 the normal diminution of size at the extremity as they approach the apical pole. The 

 breadth of the poriferous zone is rather more than half the breadth of the interpori- 

 ferous area. The pores are almost equal, the inner pores of a zone being round, the 

 outer ones very slightly elongated transversely — so slightly, however, that it is scarcely 

 perceptible. The pores are very faintly conjugate ; for the furrow between them is 

 most faint, and is produced merely by the bevelling of the narrow dissepiment. This 

 dissepiment is of uniform breadth throughout the zone. In the postero-lateral ambulacra 

 the anterior zone has 43 pairs of pores, and the posterior zone has only one pair less ; in 

 the anterolaterals the anterior zone has 35 or 36 pairs of pores, and the posterior zone 

 one pair less. The odd anterior ambulacrum has probably nearly the same number 

 of pores ; but it is impossible to state this definitely, owing to the outer portion of the 

 petal being concealed. The series of double pores (or, in other words, the petals) 

 terminate abruptly at about one third of the distance from the margin to the apex. 

 A series of only single microscopic pores is carrie d forward over the ambitus ; and there 

 is scarcely any increase in size, until half of the actinal portion of the ambulacrum has 

 been traversed ; they then increase in size and proceed to the peristome, there being still a 

 single pore to a plate. At the oral extremity of the ambulacrum there are traces of 

 two or three supplementary pores, which are probably the indications of an incipient or 

 rudimentary phyllode. Unfortunately the preservation of this portion of the test is 

 not such as to allow of definite determination. The ornamentation of the inter- 

 poriferous area within the petal is similar to that of the interambulacral plates, and 

 consists of rather widely spaced, small primary tubercles, non-crenulate, sunken in a 

 wide and deep scrobicule, the interspaces being filled with a miliary granulation, and 

 which has become confluent to a great extent, owing to dense crowding. The 

 scrobicules are as wide as, or wider than, the ambulacral plates ; and they do not occur 

 upon every plate in the series, but are usually separated by one or two blank plates, the 

 arrangement of the tubercles being quite irregular. 



In the interradial areas on the abactinal portion of the test the plates are com- 

 paratively broad, and have a sharp angular bend. The plates are uniformly covered 

 with primary tubercles and intermediate granulation similar to that already mentioned, 

 excepting that perhaps the scrobicules and their contained tubercles are slightly larger. 

 The tubercles are rather wide apart ; but at no place is the intermediate granulation 

 equal in breadth to the diameter of the scrobicule. About four irregular alternating 

 horizontal lines of primaries may be traced on a plate. The interradial plates are 

 equal in length (depth) to six or seven of the ambulacral plates at the middle of a 

 petal. On the actinal surface of the test the scrobicules are somewhat larger than 

 those in the abactinal area ; they are also more closely placed, and the intermediate 

 granulate portion is much narrower, frequently not more than the breadth of a single 

 series of granules . 



The peristome is slightly excentric in front, small, and deeply sunken. It appears 



c2 



