COELOPLEURUS FLORIDANUS. 267 



COELOPLEURUS. 



Coelopleurus Agass. 1840. Cat. Syst. Ectyp. 



General appearance of Arbacia : narrow poriferous zone, simple pairs of 

 pores above ambitus, tubercles imperforate and not crenulate. Actinostome 

 small, no cuts ; tubercles of median interambulacra have a broad bare space 

 entirely covered by minute granulations, forming undulating zigzag lines 

 from one side of the interambulacrum to the other. The tubercles of ambu- 

 lacra extend to the apex in two more or less irregular vertical rows. 



Sutural impressions along median line, at junction of ambulacral plates 

 only on the actinal side, do not extend to the ambitus. 



The spines, as far as they are known from the only living species, are 

 extraordinary, far surpassing in length those of the Diadematidae in propor- 

 tion to the test. They are long, curved triangular spines, tapering very grad- 

 ually, while on lower surface they resemble those of the other Arbaciadae, 

 and have the same cellular structure so characteristic of Arbaciadae. Out- 

 line of test less conical than in Arbacia. 



Coelopleurus floridanus 



! Coelopleurus sp. A. Agass. 1871. Bull. M. C. Z. III. p. 455. 

 ! Coelopleurus floridanus A. Ag. 1869. Rev. Ech. Pt. I. 



PI. IP. f. 14, 15. 



Among the Echini collected by Mr. Pourtales in 1868-1869, were numer- 

 ous fragments of spines of Sea-urchins which I was unable, at the time of 

 writing the Preliminary Report, to refer to any genus of Echini known to 

 me. I am able to give some definite account of the spines, having while in 

 Paris had the opportunity — thanks to Professor Bayle — of examining Mi- 

 chelin's collection now in the Ecole des Mines, containing, among other types, 

 a remarkable Sea-urchin of which only a single specimen exists, described by 

 Michelin, in Annexe A to Maillard's Notes sur lisle de Bourbon, in 1863. 



This Sea-urchin he named Keraiaphorus Maillardi; it was brought up 

 from a depth of two hundred metres on a fishing-line, and was called 

 Keraiaphorus on account of its long curved spines, resembling the antenna? 

 of Cerambycidae. The fragments of spines {PI. IP. f. 14), collected by Mr. 

 Pourtales off Tennessee Reef, at a depth of one hundred and sixty fathoms, 

 belong to this genus, but diner sufficiently in appearance to show they do 

 not belong to the same species. They are of a bright vermilion on the con- 



