2 .\<> 



XXX, utheastern South America; ioS<> 



Metres Phrixometra 



cirri with nut more than 20 much elongated segments all of 



which are markedl) longer than broad, especially the proximal 



I" 1 more than XX\ cirri, which have 10— 20 segments 



(eastern Pacific, inclu d i n g the Sea s of ( )k hot sk 



and Japan, from western Bering Sea to the 



Kermadec I s 1 a n d s and X e w Zea I a n d, an il w e s t- 



w a r d t o between M a r i o n 1 s 1 a n d and the C r o z e t s ; 



iuthwe«t of I cel and; 144 3178 Metres) . . . Thaumatometra 



f not more than XV cirri. which have not more than 10 



gments (abysses of the Pacific from west of 



Tasmania to west of Japan; 4680 — 5220 Metres) Bathymetra 



Hathrometra A. H. Clark. 



The following described species are referable to the genus Hathrometra : 



. isterias tenella Retzius, 1 783. 



Alccto dentata Say, 1825 (probably a synonym of tenella). 



Alecto sarsii Düben and Koren, 1846. 



Antedon prolixa Sladen, 1881. 



Antedon hystrix P. 11. Carpenter, 1884 (= prolixa 



Antedon exigtta P. H. Carpenter, 1888. 



Hathrometra norvegica A. H. Clark, 191 3. 



Trichometra A. H. Clark. 

 Key to the Species of the Genus Trichometra. 



a' Over 40 cirrus segments; cirri XL — LX, 40 — 45, 20 mm. long, the last 

 15 — 20 segments about as long as broad; arms 60 mm. to 65 mm. long; 

 Il'.r series and lower brachials narrow, entirely free laterally; rounded ventro- 

 lateral pro may l>e developed on the elements of the IBr series and 



first brachials, but these do not meet across the interradial areas (Hawaiian 



Islands: 21 9 Metres vexator 



.1 Less than 35 cirrus segments 



1>' more than 2^ (25 33; usually 27 — 30) cirrus segments of which those 

 ond the twelfth to twentieth are about as long as broad 

 c l 1 oi the IBi first two brachials only slightly convex 



dorsally and sharply and broadly flattened against their neighbors; arms 

 }s mm. to 65 mm. long; cirri with 25 — 30 segments, 15 mm. to 22 

 mm. long; I', with 20 2^ segm 6 mm. long; I', with to segments, 



