GENERA AKD GROUPS OE THE ECHINOIDEA. 27 



Order CIDAROIDA. 



Family Ctdarid^. 



Section I. Ambulacral pairs of pores iiniserial. 

 Genus Cidaris. 



Subgenus Goniocidaris. 

 Genus Orthocidaris. 

 Temnocidaris. 

 Polycidaris. 



Section II. Ambulacral pairs of pores biserial. 

 Genus Diplocidaris. 

 Tetracidaris. 



Section I. 



The first genus of the Cidaridse is Cidaris, Agassiz and Desor, 

 1846 ; and it is a very large one. JSTevertlieless it is well dif- 

 ferentiated from any other genus ; and it would be easily de- 

 fined had not a series of artificial divisions, raised to the dignity of 

 subgenera and even of genera, been employed to group the species. 

 It is best to give the amended generic definition, and then to 

 consider the grouping of the species. 



Grenus Cidaris, Klein, 1734 (pars); Lamarck, 1816 (pars); 



Gray, 1825 (pars). Agassiz ^ Desor, 1846, Cat. Bais., Ann. 



Set. Nat. vol. vi. p. 325. J. MuUer, 1853, JBau. d. EcJi., 



AhTil. d. Tc. ATcad. d. Wiss. Berlin, pnb. 1854, p. 123. 



Desor, 1858, Synopsis, p. 3, A. Agassiz, 1872-74, Revision 



of the Hehini, p. 252 ; and 1881, ^Challenger ' Meport, p. 33. 



C. Stewart, 1871, Quart. Journ. Micr. Sci. n. s. vol. xi. p. 54 ; 



and 1879, Trans. Linn. Soc. vol. i. p. 569. Loven, 1887, 



Ech. descr. hy Linnceus, pp. 138, 146. 

 Syn. : — Eocidaris, Desor, 1858 * ; Anaulocidaris, Zittel, 1884 1 ; 

 Discocidaris, Doderlein, 1885 J ; Schleinitzia, Studer§. 



Syn., when employed as genera and not as artificial divisions : — 

 Stephanocidaris, A. Agassiz || ; Hhabdocidaris, Desor ^ ; Leio- 



* Synopsis, p. 155. t N. Jahrb. f. Min. Bd. ii. p. 132. 



I Archiv f. Naturg. Wiegm. 1885, Heft i. p. 82, 



§ Monatsb. d. t. Akad. d. Wiss. EerHn, 1877, p. 463. 



II Eevision, p. 393. 



^ Synopsis, p. 39 ; and de Loriol, 1883, Cat. Eais. d. fich. rec. a I'lle 

 Maurice, p. 7. 



