2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 6l 



visit to London, so that these notes, though not extended, possess a 

 certain value. 



While at the British Museum I examined and took notes upon 

 about 1538 specimens, distributed in the several families as follows : 

 Comasteridae 417, Zygometridae 25, Himerometridae 180, Stephano- 

 metridae 15, Mariametridae 29, Colobometridae 84, Tropiometridae 91, 

 Calometridae 5, Thalassometridae 72, Charitometridae 64, Antedonidae 

 513, Pentametrocrinidae n, Atelecrinidae 2, Pentacrinitidae 7, and 

 Holopidae 2 ; 21 specimens examined were not identified. 



Family COMASTERIDAE A. H. Clark 



Subfamily Capillasterin;e A. H. Clark 



Genus PALJEOCOMATELLA A. H. Clark 



PALiEOCOMATELLA DIFFICILIS (P. H. Carpenter) 



Actinometra difficilis 1888. P. H. Carpenter, " Challenger " Report, Comat- 



uhe, p. 93, pi. 52, figs. 1, 2 (1). 

 Actinometra pulchella 1888. P. H. Carpenter, T. c, p. 304 (part) (1). 



1. "Challenger" Station No. 192. — One specimen. There are 

 sixteen or seventeen cirrus segments, of which the third, a transition 

 segment, is the longest, about three and one-half times as long as its 

 median diameter, slightly constricted centrally. The cirri are pro- 

 portionately very long, the distal end of the second segment being 

 nearly as far from the center of the animal as the anterior angle of 

 the IIBr axillary. The outer cirrus segments have rather strong 

 dorsal processes. 



On page 93 of the " Challenger " Report Carpenter, under the 

 name of Actinometra difficilis, refers to this specimen, citing the two 

 figures on plate 52, and says of it, " the two outer radials [*. e., the 

 two ossicles of the IBr series], the two distichals [IIBr series], and 

 the first two brachials are respectively united by syzygy;" but later 

 (p. 306), referring to the same specimen and the same figures, he 

 says, " after repeated changes of opinion I have come to the con- 

 clusion that there is a bifascial articulation [i. e., synarthry] in each 

 case." 



The former meager diagnosis, combined with the reference to the 

 figures, in spite of the fact that it is based upon misconception of the 

 structure of the animal and is therefore wholly erroneous, serves, 

 according to the rules of the International Committee on nomen- 

 clature, to establish the name difficilis, even though he suppressed 

 this name later. 



