2 59 



The IBr, (axillaries) are nearly as broad as long, almost triangular, the lateral angles 

 jüst in apposition with the lateral angles of the adjacent axillaries, and bear a moderately 

 developed rounded posterior process. 



The edges of the ossicles of the IBr series and of the brachials are prominently everted 

 and spinous; the dorsal surface of the lower brachials is also more or less thickly covered 

 with very fine spines. There is a faint shallow median groove on the IBrj and IBr 3 . 



The ends of the proximal cirrus segments are very spinous, and their dorsal surface is 

 slightly carinate. 



P x is excessively delicate ; the segments after the third are greatly elongated with 

 expanded and finely spinous distal ends. 



2. Tonrometra remota (P. H. Carpenter). 



P. H. Carpenter. "Chaüenger" Reports. Comatulae, iSSS, p. 1S4. pi. 29, figs. 5 — 9 {Antedon 



remota). 



A. H. Clark. Smithsonian Miscellaneous Collections, vol. 61, 1913, N° 15, p. 66 [Thaumato- 



metra remota). 



II. Family Pentametrocrixidae A. H. Clark. 



Key to the Genera of the Pentametrocrinidae. 



a 1 Ten radials and ten (undivided) arms Thaumatocrinus 



a 3 Five radials and five (undivided) arms Pentametrocrinus 



Thaumatocrinus P. H. Carpenter. 

 Key to the Species of the Genus Thaumatocrinus. 



a 1 Small species with a small centrodorsal which bears fewer than twenty cirri 



b 1 cirri XV — XX, excessively slender, with enormously elongated segments of 

 which the third is about four times as long as the diameter of the expanded 

 proximal end, and the fourth is six times as long as its proximal diameter 

 (extreme south of the Indian Ocean) . renovatus - 1 ) 



\y cirri XI — XIII (very rarely more), slender, but not excessively so, with less 



elongated segments than in the preceding, the third never being more than 



twice as long as broad, and the fourth usually less than four times as 



long as the diameter of the expanded ends (south west of I celand) . jungerseni 



a 2 Larger species with a large and broad centrodorsal which bears more than 



forty cirri 



b 1 second brachial more than twice as long as the first, which is dispropor- 



tionately small (southern Japan) borealis 



1) Synonym Promackocrinus abyssorum P. H. Carpenter. 



