62 THE FOSSIL ECHINOIDEA 



Ambulacra small, short, petaloid, subequal ; the odd anterior ambulacrum aborted. 

 Poriferous zones subequal, pores conjugate. 



Apical disk eccentric in front, small ; generative pores four, and madreporiform 

 body central. 



Peristome transversely oval, subcentral or very slightly eccentric in front, with 

 perpendicular wall reaching upward into the body-cavity. No bourrelets. Phyllodes 

 very faintly developed. Buccal pores opening into the peristomial margin, with a small 

 granule-like prominence over each standing at the extreme edge of the peristomial 

 ring. 



Periproct marginal, transverse (1). 



Tuberculation small, homogeneous, in sunken scrobicules ; intermediate space 

 subgranular and confluent. 



This genus is closely related to Echinolampas ; indeed the test might at first 

 sight be regarded as that of a young or abnormal form ; but the small and subequal 

 ambulacral petals, the aborted odd ambulacrum, the very anterior apical disk, together 

 with the form of the test and the character of the peristome appear to demand a 

 generic separation. Furthermore, no true Echinolampas has hitherto been found in 

 the Eanikot series, whilst the form under notice is recorded from three localities. 



Eolampas also occurs in the Khirthar series ; and although these beds are very rich 

 in Echinolampas, we are unable to refer the form (apart from its special characteristics) 

 to the young of any species there present. 



1. EOLAMPAS ANTECUESOR, sp. nov. Plate XVII, Figs. 11-16. 



The test is tumid, highest in front, with a precipitous anterior portion and a more 

 gradually sloping and curved posterior part, the top of the test being on a very gradual 

 backward slope. It is longer than it is broad, and broader than high. The transverse 

 outline is nearly hemispherical ; and the marginal outline is oval or elliptical, the greatest 

 breadth being about central. The margins are tumid, the actinal surface is slightly 

 hollowed out or concave, there is barely a keel posteriorly, and the anterior and lateral 

 parts of the test overhang the base. The apical system is very eccentric in front, and 

 the peristome is subcentral ; the periproct is just above the margin and is small. The 

 apical system is small ; there are four small generative plates and pores ; and the 

 madreporic body is small and central. The ambulacral rosette is small in relation to 

 the size of the test ; and the ambulacral petals end remotely from the margin, and 

 the posterior pair more than their own length from the posterior end of the test. 



The anterior ambulacrum has no double pores, but there is a series of broad 

 grooves amongst the ornamentation of the test in their position ; the grooves are 

 more numerous than the pairs of pores of the other ambulacra, and no trace of a 

 pore is to be seen in them. A worn test shows neither grooves nor pores in the region 

 of the odd ambulacrum. 



The antero-lateral ambulacra form a widely open angle, being nearly transverse in 

 their position ; they are petaloid, not closed, and they are slightly broader than the 

 others. The anterior poriferous zone is straighter than the posterior ; and the pairs are 



