interiorly and exteriorly, half again as broad as the median length; the next two brachials are 

 hly oblong, the following becoming triangular, about as long as broad, and after the basal 

 thiril of the arm wedge-shaped, and elongate distally. The distal edge of the brachials is 

 rather prominent and finelj spinous; their dorsal surface is longitudinally striate. 



Sj ygies oei the third and fourth brachials, again hetween the ninth and tenth 



and fourteenth and fifteenth, and distall) at intervals of two oblique muscular articulations. 



The interradial portions ol the perisome of the disk bear numerous calcareous concretions 

 qual in size which, entirely and rather widely separated from each other, are elevated 

 above the general surface in the shape of thick papillae. 



i' i- I) large and stout, and recalls I'. in certain varieties of Oligometra serri- 



pinna\ it is o mm. long, composed of i: segments of which the fust is about as long as 



. 1. and the remainder ahorn half again as long as broad; the distal border on the outer 



a;iv from the disk: is everted and fmelv spinous. 



I' is 3 mm. Ion- with 10 segments; it resembles P> but is proportionately smaller, and 

 the outer segments have a greater development of spines. 



1' is 3 mm. long with io segments, more slender than P,. the component segments 

 mor- ite with more everted and spinous distal ends. The following pinnules resemble I 1 . 



but slowly increase in length. 



The distal pinnules are j mm. long, very slender, with tg segments of which all but the 

 first two an- greatly elongated with swollen articulations and overlapping and spinous distal ends. 



1' is absent from seven arms, and present on three. 



The colour in life is pale orange and yellow, according to a note by Mr F. M. Chamberlain. 



The specimen described in Cat. X" 36050 U. S. National Museum. 



2. Erythrometra ruber \\. II. Clark). 



A. 11. Clark. Proc. U.S. National .Museum, vol. 33, 1907, p. 146 {Antedon rul 

 Proc. U.S. National Museum, vol. 34, 190S, p. 316 [Erythrometra rul 



Hypalometra A. II. Clark. 



The only species in the -rnus Hypalometra is 

 1. Hypalometra defecta 1'. II. Carpenter). 



1'. 11. Carpenter. "Challenger" Reports. I omatulae, 1888, pp. 54, 206, 207. 3 . 378 



>i t t - Jon defect 

 Haki i.aii:. Memoirs Mus. Coitip. Zool., vol. 27, 1912, N 4, p. 3S1. pi. e. figs 1 4; pi. 14, 

 1 1 . Intedon de/, 



• 



Nanometra A. 11. (huk. 



Key to il). ,1" the i inius Nanometra. 



1 irri LXX, |; 17. 25 mm. t.. jo mm. long; distal borders of the radials and 

 bon i the [Br series usually unmodified, rarely hearing tubercles; 



