CLARK : THE CIDA1UDAE. 197 



Moderate or large (20-50 mm. h. d.) ; coronal plates 6-11; abactinal 



system generally about .40 h. d., and only partially covered with 



miliary tubercles of various sizes; primaries seldom pointed and 



with no covering of woolly calcareous hairs. 



Abactinal system equal to, or larger than, actinostome; coronal plates 



with tubercles near vertical suture much smaller than those next 



to areolae tubaria 



Abactinal system smaller than actinostome ; coronal plates with 



tubercles rather large and of nearly uniform size umbraculum 



Each coronal plate with numerous miliary tubercles, so that median inter- 

 ambulacral area is usually covered by them, except on sutures ; if bare 

 sunken areas are conspicuous at all, it is only on inner half of hori- 

 zontal sutures; median ambulacral area with numerous miliary tuber- 

 cles, tending to cover it, so that it is never wholly sunken and bare. 

 Large (25-50 mm. h. d.) ; abactinal system almost uniformly covered with 

 small tubercles; miliary tubercles on ambulacra, in horizontal series 



with deep furrows between geranioides 



Small (15-35 mm. h. d.) ; abactinal system not uniformly covered with 

 small tubercles ; miliary tubercles in median ambulacral area never 

 conspicuous, but often filling up entire space. 

 Lower edge of ambulacral plates occupied by minute tubercles, leav- 

 ing distinct bare spaces forming small, rectangular pits, which 

 alternate with each other; primaries white or whitish in contrast 



with reddish-yellow secondaries fiorigera 



No definite arrangement of tubercles on ambulacra clear, and no dis- 

 tinct bare pits; primaries not "whitish in contrast with" darker 

 secondaries. 

 Test high, .60-.70 h. d. ; abactinal system much less than vertical 

 diameter; primaries more or less covered with calcareous hairs 

 and usually with a conspicuous, flat, horizontal plate just above 



collar mikado 



Test low, .50-.60 h. d. ; abactinal system nearly or quite equals ver- 

 tical diameter ; primaries with relatively few, long and stout 

 thorns, but otherwise smooth biserialis 



G-oniocidaris clypeata. 



Goniocidaris clypeata Doderlein, 1885, Arch. Naturg., 51 Jhrg., 1, p. 82. 

 Plate 6, Plate 4, figs. 8-20, Jap. Seeigel, Doderlein, 1887. 



This is one of the interesting species discovered by Doderlein in Japan, and 

 will be easily recognized from his excellent figures and description. The prevail- 

 ing color is whitish, pinkish, or brown of some shade. The material collected by 

 the " Albatross " shows beyond question that the little cidaroid described by 

 Doderlein ('87) as Porocidaris gracilis is a small example of this species, in 

 which the spines with enormously expanded tips are wanting. The " Siboga " 

 cidaroid called C. hirsutispbius by de Meijere (: 04) is also evidently a young 

 example of this species ; the secondaries of clypeata are frequently exactly like 

 de Meijere's figure. Except this "Siboga" specimen, clypeata is known only 

 from the vicinity of Japan. 



