20 FOSSIL ECHINI OF THE WEST INDIES. 



is more apparent than real. The interporiferous areas are very broad, with 

 two rows of regular granules placed on the border of the poriferous areas, 

 the intermediate space occupied by two other ranges of finer granules, 

 less regularly arranged and less equal in size. Interambulacral tubercles 

 prominent, strongly mammillate, perforate, non-crenulate. Scrobicules 

 moderately developed, rounded dorsally, subelliptical as one approaches 

 the peristome, bordered with a circle of mammillate granules, the space 

 without this circle being covered with smaller tubercles, irregular and rather 

 widely scattered. 



Height of specimen 15 mm., diameter 26.5 mm., width of ambula- 

 crum at the mid-zone 4 mm., width of interambulacrum at the same 

 plane 12 mm. Cotteau says that there are 6 interambulacral plates in 

 a column, but I found that, in some areas at least, there are 7; they 

 are, however, very incomplete and worn dorsally. 



This species is easily distinguished from the other fossil species 

 of Cidaris of the region by the widely separated ambulacral pores of a 

 pair connected by a furrow, as in the living genus Phyllacanthus. 

 When compared with an adult Recent Cidaris bartletti (A. Ag.) from 

 Barbados (M. C. Z. No. 133), the differences are slight, the only 

 tangible one being the more numerous tubercles and granules on the 

 coronal plates. About 12 ambulacral plates at the mid-zone abut 

 against a single interambulacral plate. Interambulacrum with 6 

 plates in a column, as stated by Cotteau, though in one area at least 

 7 existed, as I counted that number. Interambulacral plates prom- 

 inent, strongly mammillate, non-crenulate. This species, loveni, 

 although of considerable antiquity geologically, is certainly very 

 similar to the Recent bartletti. 



Cotteau does not mention more than one specimen of this species 

 and only says very rare. The specimen gives the same measurements 

 as Cotteau's, and while in part much worn, it is evidently the holo- 

 type of which Cotteau's figures were quite freely restored, especially 

 in the dorsal view. 



Eocene, St. Bartholomew limestone, island of St. Bartholomew, 

 Guppy Collection ex Cleve, holotype, 1 specimen, U. S. Nat. Mus. 

 No. 115415. 



Cidaris clevei Cotteau. 



(Plate 1, Figure 11.) 



Cidaris clevei Cotteau, 1875, Kongl. Svens. Vet. Akad. Handl., vol. 13, No. 6, p. 11, plate 



1, figs. 15, 16. 

 Cidaris melitensis Guppy (pars), 1882, Scient. Assoc. Trinidad, Proc., part 12, p. 194. 



The following is an extract from original description of this species : 

 Species of small size, circular, moderately elevated, ambulacra narrow, 

 straight, slightly sunken, ambulacral area with 6 rows of granules nearly 

 equal in size, the 6 rows being reduced to 4 ventrally and dorsally. Inter- 

 ambulacral tubercles small, perforate, non-crenulate, 7 to 8 plates in a 

 column. Scrobicules small, narrow, never meeting at the base. Space 

 around scrobicules filled with small granular tubercles. 



