REPORT ON TIIE ASTEROIDEA. 397 



Order CRYPTOZONIA, Sladcn, 1888. 

 Family Linckiid.e, Perrier, 1875, emend. 



The family Linekiida), if tLe genera Ch&taster and Mctrodira be excepted, is one 

 which presents great solidarity in its morphological facies. The two genera just named 

 differ, however, so greatly in their general character from the other forms included in the 

 family that I have placed them in distinct subfamilies. The plan of their structure is more 

 in consonance with that of the Linckiidae as a whole than with that of any other family, 

 but the details of their structure place them as very divergent members of the family, and 

 warranty in my estimation, the course I have taken for bringing into prominence their 

 aberrant and transitional character. 



Viguier 1 first referred Chastaster to this family, but he removed Fromia, Ferdina, 

 and Mctrodira to his family Goniasteridae. This latter step I am unable to approve, and 

 I agree with Perrier in ranking these genera under the Linckiida?. 



It has seemed to me useful to reinstate some of the genera recognised by Gray, which 

 have been absorbed by subsequent writers on what appear to me insufficient grounds. 



Synopsis of the Genera included in the Family Linckiid.e. 



A. Abactinal piates with internal supplemental plates. Abactinal plates with 



paxilliform tabula .......... CH^TASTERiNiE. 



a. A single genus . Ckxtaster. 



B. Abactinal plates devoid of internal supplementary plates ; not forming paxil- 



liform tabula, 

 a. Abactinal and marginal plates granulose and not bearing spines . . LmcsitSM. 



a. Devoid of superambulacral plates. 



a. Adambulacral armature in two or more series. Papulae on 

 the actinal surface. Marginal plates larger than the 

 others. Abactinal plates comparatively small . . . Fromia. 



ji. Adambulacral armature in a single series. No papula? on 

 actinal surface. Marginal plates not larger than the 

 others. Abactinal plates large and more or less convex . Ferdina. 



b. With superambulacral plates. 



a. Abactinal plates in regular longitudinal series. Adambu- 

 lacral armature in two unequal series ; the outermost 

 large and spiniform. Papulae on the actinal surface. 

 i. Abactinal and marginal plates granulose or bearing 

 squamiform papilla;. 



1. Papular areas not confluent laterally. Madre- 



poriform body simple ..... Ophidiaster. 



1 Archives dc Zool. exper,, 1878, t. vii. p. 147. 



