FOSSIL ('RINOIl)S. 143 



1. Substantially all non-pinnulate dicyclic luadunata have round facets, 

 less than the width of the radials, and without complete transverse articulation. 



2. All pinnulate dicyclic Inadunata (except Poteriocrinus) have a well 

 developed and constant transverse articulation, with wide, straight facets the 

 full width of the radials. 



3. The first of these groups, being early specialized, was first extinguished, 

 ending, so far as known (save in a feeble reminiscent or sporadic way), before 

 the close of the Lower Carboniferous; while the second persisted to the present 

 time. 



4. Much the same thing can be said of the Flexibilia — all being actually 

 or potentially dicyclic — viz : 



o. That the non-pinnulate (Flexibilia Impinnata) for the most part, whether 

 with wide facets or narrow, have a specialized articulation, apparently without 

 a complete transverse ridge : The Palaeozoic Flexibilia ; while — 



h. All pinnulate (Flexibilia Pinnata) have wide and straight facets, with 

 transverse articulation (except Uintacrinus, where it is modified by disuse, 

 resulting from the incorporation of brachials by interbrachial plates) : Apio- 

 crinidae, Bourgueticrinidae, and the Comatulids. 



In view of these facts, I am unable to see any convincing reason for abandon- 

 ing the arrangement and definition of these two Inadunate families as made by 

 Wachsmuth and Springer. The name Poteriocrinidae could be bettered, it is 

 true; but a name is a name in zoology, if validly established and its meaning 

 clear, even if not so appropriate as others. The genus Poteriocrinus, although 

 not perfectly typical, must by the preponderance of characters remain in the 

 family, and so the family name is not wholly incongruous or misleading, after all. 



Whether to treat these two divisions of the Inadunata as suborders, and call 

 them Cyathocrinoidea and Poteriocrinoidea, or simply families as before, is a 

 matter of detail, depending upon the general plan of treatment. What Bather 

 calls suborders and families, may with equal convenience be treated as families 

 and subfamilies; and therefore for the present I prefer to retain the terms as 

 originally employed by us. Accordingly the family definition will be: 



Dicyclic Inadunata; pinnulate; with straight muscular 

 articulation, facets usually filling entire distal face of 

 radials Poteriocrinidae. 



Before proceeding with an analysis of the genera in this family, which I set 

 out to give, it is necessary to clear uj) a few matters of nomenclature that will 

 make more confusion the longer they are ignored. 



