CLARK: THE CIDARIDAE. 199 



accepted, more adequate descriptions are necessary, and the differences between 

 the three species made more tangible. That C. fimbriate), de Meijere (: 04) is iden- 

 tical \i'\\k Jlorigera seems to me practically certain. 



Goniocidaris mikado. 



Discocidaris (Cidaris) mikado Doderlein, 1885, Arch. Naturg., 51 Jhrg., 1, p. 80. 

 Goniocidaris mikado Doderlein, 1887, Jap. Seeigel, p. 15. 



Plate 7, Jap. Seeigel, Doderlein, 1887. 



This is another of the Japanese echinoids, which Dbderlein's excellent work 

 has given us. Although undoubtedly nearly related to the preceding species and 

 to clypeata, it is perfectly distinct and easily recognized. The minute, often 

 nearly spherical, secondary spines are very characteristic. The color is almost 

 cream-white, with a purplish tint abactiually and on the primaries. Specimens 

 have as yet been taken only in the vicinity of Japan. 



Goniocidaris biserialis. 



Stephanocidaris biserialis Doderlein, 1885, Arch. Naturg., 51 Jhrg., 1, p. 79. 

 Goniocidaris biseiialis Doderlein, 1887, Jap. Seeigel, p. 10. 



Plate 5, Jap. Seeigel, Doderlein, 1887. 



This species is quite unlike the preceding in its general appearance, but re- 

 sembles it in the obliteration of the bare depressed areas on ambulacra and in- 

 terambulacra which characterize the typical members of the genus. The color of 

 biserialis is quite variable, ranging from dull brownish-yellow, with more or less 

 of a green tint, to yellow, olive-green, or brownish-red. It is known only from 

 the vicinity of Japan. 



POLYCIDARIS. 



Polycidaris Quenstedt, 1858, Der Jura, p. 644. 



Plate 79, fig. 69, Der Jura, Quenstedt, 1858. 



Test of moderate size, circular at ambitus, flattened ; eoronal plates numerous 

 (9-15) ; areolae somewhat deeply sunken, merging together throughout the entire 

 vertical series, even at ambitus; median interambulacral areas more or less bare 

 and depressed ; ambulacra narrow, .15-22 of interambulacra, straight ; poriferous 

 zones little sunken ; median ambulacral area with only a single marginal series of 

 small tubercles ; pores oblique, near together, separated by a slight elevation. 

 Abactinal system ? Actinostome ? Spines and pedicellariae ? 



Doderlein ('87) appears to think this genus is near Dorocidaris, but to me it 

 is clear that its relationships are with Goniocidaris. Except for the narrow am- 

 bulacra and the merged areolae, P. nonarius is strikingly like G. umbraculum. 

 Doderlein lists 5 species, all from the Jurassic strata of Europe. 



