OF WESTERN SIND. 155 



2. EcHiNOLAMPAS SUBCONICA, Dwncan & Sladen. Plate XXVIII, Figs. 7-11. 



Test of moderate size. Marginal contour suboval, slightly expanded in the 

 posterior region of the lateral interradia, evenly rounded in front, feebly rostrate 

 behind. The length is rather greater than the breadth, being in the proportion of 

 1 : 0-86. The dorsal surface is moderately high, subconical, and rather pointed at the 

 apex, which is excentric in front, and the greatest height is rather less than three fifths 

 of the length. Seen iu longitudinal profile, the anterior and posterior slopes of the 

 abactinal surface appear as two gentle, evenly-rounded, convex curves of low curvature, 

 culminating rather sharply or pointedly at the apex ; the anterior slope is much shorter 

 and more precipitous than the posterior, and continues, without any interference, in its 

 course over the thick and well-rounded anterior margin ; the posterior slope is less 

 inclined than the anterior, and extends as a regular convex or subparabolic curve from 

 the apex to the margin of the periproct, just below the ambitus, the posterior margin 

 of the test being much thinner and less tumid than the anterior. Seen in transverse 

 profile, the abactinal surface slopes rather rapidly from the apex, and the curvature 

 being slight, the conical appearance is greatly emphasized, the outline passing without 

 interruption over the moderately thick and well-rounded margins. The actinal surface 

 is pulvinate, the peristome being depressed and the surrounding test being tumid, 

 sloping inwards to the mouth, and outwards with a slow and gradual curve to the 

 ambitus. The anterior and the posterior portions of the test are the most tumid ; and 

 the test, when placed on a level surface, rests on these regions of the test entirely. 

 The lateral interradia are slightly more tumid along their median line, which gives, 

 though faintly, a rather undulating appearance to the actinal area. 



The apical disk is excentric in front. In the specimen under notice there are 

 only two generative pores, the left anterior and the left posterior pores being aborted ; 

 the whole of the centre of the disk is occupied by a rather large madreporiform body, 

 which is not prominent, but is ornamented with a few moderately large granules widely 

 spaced and irregularly placed. 



The ambulacral petals are long and narrow. The posterior pair are the longest 

 and the broadest ; the anterior pair and the odd anterior ambulacrum are subequal in 

 length, but the odd anterior petal is narrower than the pair. The shape of the petals 

 is lanceolate and very attenuate and tapering to the apex, and their contraction at the 

 outer extremity is very slight. The greatest breadth of the postero-lateral petal is 

 7 millim., or -xwon of the length of the test. The poriferous zones in all the petals are 

 slightly unequal ; the posterior zone in the posterior petals and the anterior zone in 

 anterior petals being shorter than the companion zones in the respective petals, the 

 difierence, however, not being more than five or six pairs of pores in the anterior petals, 

 and less in the posterior petals. In the anterior pair of petals the posterior zone is 

 more curved than the anterior zone ; it is boldly convex into the lateral interradia, and 

 presents a faint trace of sigmoid curvature in consequence of the zone at the extreme 

 tip being slightly bent backwards. The posterior zone of the posterior petals is also 

 slio'htly more curved than the companion anterior zone, and there is also the same faint 

 outward turn of the poriferous zone at the extremity ; but neither character is developed 



