CLARK: THE CIDARIDAE. 



177 



Genus. 



Cidaris . . 



Phyllacanthus 



Goniocidaris 



Diploeidaris . 

 Porocidaris . 



Polycidaris . . 

 Orthocidaris 

 Ternnocidaris . 

 Stephanocidaris 



Chondrocidaris 

 Dorocidaris . 

 Tetracidaris 

 Tyloeidaris . 

 Stereocidaris 



Tretocidaris . 

 Acanthocidaris 

 Centrocidaris 

 Anomocidaris 



Aporocidaris 



Calocidaris . 

 Austrocidaris 



Author. 



Leske. . . . 

 Brandt . . . 

 L. Agassiz et 

 Desor . . . 

 Desor .... 

 Desor .... 



Quenstedt 

 Cotteau . 

 Cotteau . 

 A. Agassiz 

 A. Agassiz 

 A. Agassiz 

 Cotteau . 

 Pomel 

 Pomel 



Mortensen 

 Mortensen 

 A. Agassiz 

 A. Agassiz 



Clark . 

 A. Agassiz 



Clark . 

 gen. nov. 

 gen. nov. 



and 

 and 



Year. 



1778 

 1835 



1846 

 1854 

 1854 



1858 

 1862 

 1862 

 1863 

 1863 

 1869 

 1872 

 1883 

 1883 



1903 

 1903 

 1904 



1907 



1907 

 1907 

 1907 



Type-species. 



tribuloides Lamarck .... 

 imperialis Lamarck .... 



geranioides Lamarck .... 



gigantea Agassiz 



veronensis Desor, but of re- 

 cent species, purpurata Wy v. 

 Thomson 



multiceps Quenstedt . . . . 



inermis A. Gras 



magnifica Cotteau 



bispinosa Lamarck . . . . . 



gigantea A. Agassiz . . . . 



abyssicola A. Agassiz . . . 



reynesi Cotteau 



gibberula L. Agassiz et Desor . 



cretosa Mantell, but of recent 

 species, grandis Doderlein . 



bartletti A. Agassiz . . . . 



curvatispinis Bell 



doederleini A. Agassiz . . . 



japonica Doderlein 



milleri A. Agassiz . . * * . 



micans Mortensen 



canaliculata A. Agassiz . . . 



Number 



of Recent 



Species. 



21 genera and 60 recent species. 



parts. The other abbreviations used are self-explanatory. The " vertical 

 diameter " means the vertical distance from the margin of the abactinal 

 system, at the end of an ambulacrum, to the lowest part (usually several 

 millimeters distant from the edge of the actinostome) of the same am- 

 bulacrum, measured with a pair of dividers. When the measurement 

 from the centre of the abactinal system is normally very different from 

 this, special reference is made to the fact. In all cases maximum 

 measurements are used for comparison ; thus, when it is said that the 

 " abactinal system equals .40 h. d.," what is meant is that the greatest 

 diameter of the abactinal system (it is not always circular) equals .40 

 of the greatest diameter of the test. " Primary spines about equal to 

 h. d." means that the longest primary is about equal to the greatest di- 

 ameter of its own test. The relative position of the pores of a pair is 

 indicated as " horizontal " or " oblique," according to whether a line 

 drawn outward from the tubercle on the margin of the median am- 

 bulacral area, at right angles to that margin, passes above both pores or 

 vol. li. — no. 7 12 



