406 COELOPLEURUS. 



COELOPLEURUS. 



Coelopleurus Ag ass., 1840, Cat. Ectyp. 

 (Sec Pari II. p. 207.) 



Coelopleurus floridanus 



! Coelopleurus sp. A. Ac, 1871, Hull. M. C. '/.., II. 

 ! Coelopleurus floridanus A. At;., l s 7 •_>. Rev. Ech., l't. I. p. 102. 

 (See Part II. p. ->G7.) 



Pl.ir.f. 14-15. 



Straits of Florida. 



Coelopleurus Maillardi 



! Keraiaphorus Maillardi Mica. 1862, Mull, Bourbon Ann. A. 

 ! < •oeloptt urus Maillardi A. Ac, 1871, bull. M. C. Z. II. p. 150. 



Test somewhat compressed. Ambulacral zones broad, covered with two 

 principal vertical rows of tubercles, becoming larger towards ambitus; on the 

 actinal side of test, of uniform size with the interambularral primary tu- 

 bercles; the tubercles of both zones remarkably uniform in size. Median 

 ambulacra! zone above ambitus carrying few secondary tubercles, forming an 

 irregular vertical median row ; the median line of ambulacral space is 

 pitted with sutural impressions between the actinostome and ambitus. There 

 are but two principal vertical rows of primary interambulacral tubercles, 

 extending only a short distance above ambitus; the abactinal part of the 

 median interambulacral space is covered by miliaries of uniform size, ar- 

 ranged in ridges, running in S-shaped curves from the base of one plate to 

 the angle of the opposite plate, across the bare part of the zone. This bare 

 part is further circumscribed by a broad band of secondary tubercles and 

 larger miliaries, extending on each side of the interambulacral zone, next to 

 the poriferous zone, between it and the principal vertical rows of tubercles, 

 from the abactinal system to the actinal surface. Poriferous zone is narrow; 

 pores, arranged in vertical tires of three round base of primary tubercles, do 

 not become petaloid round actinostome. Primary tubercles neither perforate 

 nor crenulate; no well-defined scrobicular circle. Actinostome of moderate 

 size, with slight cuts, the narrow, sharp lips of cuts well defined. Abactinal 

 system has a nearly circular anal system, surrounded by a row of large mil- 

 iaries on the edge of the genital plates, which arc of uniform size with geni- 

 tal openings situated in centre of plate ; madreporic genital slightly largest. 

 Ocular plates broadly triangular ; ornamentation of abactiual plates formed 



