172 THE FOSSIL ECHINOIDEA 



9. EcHiKOLAMPAS LEPADipOEMis, Buncan & Bladen. Plate XXXI, Figs. 6-10. 



Test of small size. Marginal contour roundly oval, slightly more pointed poste- 

 riorly than anteriorly. The greatest breadth is nearly nine tenths of the length, or as 

 0-89 : 1. The dorsal surface is regularly convex, springing from the comparatively 

 thin margins. The greatest height is one half the length, or as 0-51 : 1, measured from 

 the resting-plane of the test. The actinal surface is concave, the resting-plane of the 

 test being close to the margin, which is thin and overhanging, merging imperceptibly 

 into the dorsal curve. There is a faint carination along the median line of the poste- 

 rior interradium. Seen in longitudinal profile, a slight flattening of the convexity is 

 apparent at the apex, and the curvature anteriorly is fuller and more tumid than 

 posteriorly, the posterior curve being more extended and gradual. The transverse 

 profile is faintly but distinctly subconoid in outline. 



The apical disk is excentric in front, its distance from the anterior margin being 

 about three tenths of the length of the test. The anterior pair of generative pores are 

 closer together than the posterior pair ; and the ocular pores are small and microscopic. 



The ambulacral petals are long, narrow, and subelliptical in outline. The ante- 

 rior pair and the odd anterior petal are subequal, both in length and breadth. The 

 poriferous zones are narrow and uniform ; the anterior zone in the anterior pair, and 

 the left zone in the odd anterior petal being the shortest by a few pairs of pores. The 

 posterior petals are longer and also slightly narrower than the anterior petals ; and the 

 anterior zone of the posterior petal is longer by five or six pairs of pores, and is 

 distinctly broader than the companion posterior zone. Both the inner and the outer 

 series of pores are round, and those of a pair are united by a conjugating furrow, the 

 adjacent furrows being separated by well-defined costse, bearing a single line of miliary 

 granules. The interporiferous areas are very faintly tumid. The interradial areas of 

 the test are uniform and undisturbed by any sudden tumidity on the abactinal region, 

 excepting the decided carination of the odd posterior interradium previously mentioned. 

 At the margin of the actinal surface there is a slight tumidity in the posterior column 

 of the lateral interradia, but of very small development. 



The peristome is large and excentric in front, transversely subpentagonal,. with 

 rounded angles. There is a high vertical wall extending upwards, covered with a 

 uniform granulation, and the buccal pores of the ambulacra open conspicuously below 

 the margin. Bourrelets are present, and the phyllodes are well developed for this 

 genus. The widely extended concavity in which the peristome is situated is remarkable. 



The periproct is large, transverse, and inframarginal, the plane of the orifice having 

 apparently been at an angle to the actinal surface ; but unfortunately the test has 

 sustained fracture in this region. 



The ornamentation of the test is uniform, the scrobiciiles are comparatively large 

 and closely placed, with the intervening miliary granulation large and confluent. 



BemarJcs. This form is unlike any of the other Indian species of Echinolampas, 

 and we know of none with which it can be confounded. In longitudinal profile it 

 bears some resemblance to E. globulus, Laube ; but it differs in the greater breadth in 



