340 REPORT ON THE STATE CABINET. 



Lepidechinus has a double range of poral or ambulacral plates, and two 

 pores in each plate near the outer end, making two double rows of pores 

 only ; while the interambulacral areas are many times as wide as the 

 ambulacral areas, and differ from those of Palechinus in having more 

 than five ranges of plates. 



Lepidechinus babispinus, n. s. 



PLATE IX, FIG. 10. 



Body spherical or depressed spheroidal. Interambulacral area having 

 from nine to eleven ranges of imbricating, mostly hexagonal plates, 

 in their widest part, which gradually decrease in size towards the 

 upper end ; while on the lower side the central ranges terminate before 

 reaching the apex, and the outer ranges only reach the oral aperture. 

 The plates are imbricated from below upwards, and from the centres 

 of the areas outwards ; the central range overlapping those adjoining 

 on either side. The ranges immediately bordering the ambulacra 

 are small, and mostly furnished with small spines. The plates of 

 the next range are the largest of the body ; each alternate plate in 

 the upper part larger than the adjacent one, and having a strong 

 central spine. Each of the other plates of the areas, in the upper part 

 of the body, bears one or more spinules ; while in the central 

 portion these become strong spines. Ambulacral areas narrow, 

 contracted towards their upper ends, composed of a double series 

 of very short curved poral plates, alternating and interlocking 

 at their adjacent margins ; each plate pierced by two small pores 

 near the outer extremity. There are from three to four of these 

 plates in the space of one-tenth of an inch, and they are slightly 

 imbricated in a direction opposite to those of the interambulacral 

 areas. 



The summit of the specimen is composed of several ornamented plates, 

 arranged in the form of a pentagon ; the precise number and form of 

 these plates cannot be determined. Just within one of the angles of this 

 pentagon, and occupying the position of the madreporic tubercle in 

 modern Echinoderms, there are impressions of what appear to have 

 been the bases of several [six 1] plates, arranged in a circle, and having 

 precisely the appearance of the ovarian pyramid as seen in Agelacbinus. 

 The oral aperture has been quite small, and centrally situated. 



