REPORT ON THE ASTEROIDEA. 397 
Order CRYPTOZONIA, Sladen, 1888. 
Family Linck11p&, Perrier, 1875, emend. 
The family Linckiide, if the genera Chxtaster and Metrodira 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 Linckiidze 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 
warrant, in my estimation, the course I have taken for bringing into prominence their 
aberrant and transitional character. 
Viguier’ first referred Chetaster to this family, but he removed Fromia, Ferdina, 
and Metrodira to his family Goniasteride. This latter step Iam unable to approve, and 
I agree with Perrier in ranking these genera under the Linckiide. 
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 Lincxup. 
A. Abactinal plates with internal supplementary plates. Abactinal plates with 
paxilliform tabula . : : 9 : I D : . . CHTASTERINE. 
a, A single genus : a 5 : : . . : é : 3 Chetaster. 
B. Abactinal plates devoid of internal supplementary plates ; not forming paxil- 
liform tabula. 
a. Abactinal and marginal plates granulose and not bearing spines . . Linckiina. 
a. Devoid of superambulacral plates. 
a, Adambulacral armature in two or more series. Papule on 
the actinal surface. Marginal plates larger than the 
others. Abactinal plates comparatively small : : : Fromia. 
f. Adambulacral armature in a single series. No papule 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. Papule on the actinal surface. 
i. Abactinal and marginal plates granulose or bearing 
squamiform papille. 
1, Papular areas not confluent laterally. Madre- 
poriform body simple. : ; : 3 Ophidiaster. 
1 Archives de Zool. expér., 1878, t. vii. p. 147. 
