[66 



Thalassometra A. II. ( lark. 



Kej l ■ the Species of the Genus Thalassometra. 



i Eighth and following branchials with two or three long curved spines near 

 the distal edge, whicl ne very prominent in the outer portions of the 



arms; margins of the ossicles of tin- IBr series and lower brachials frinered 

 with very prominent bluiu spines; radials, elements of the IBr series and 

 first two brachials with a rounded and spinous centre raised above the 

 lateral portions; io arms, 50 mm. long; cirri about XXV, 30 — 35(Crozel 



[slands 2926 Metres) öispinosa' 



a Without two or tliree long curved spines near the distal edge of tin- brachials, 

 which have more or less overlapping and finely spinous distal edges; rarely 

 the centra] ])ortion of the laterally compressed outer brachials may be produced 

 into a single broad, dorsoventrally flattened median overlapping spine 

 1)' not more than 30 cirrns segments; cirrus sockets irregularly place d on 

 ,i hemispherical centrodorsal in one irregular row "f 15, and an irregular 

 |>artial second row 



c' very numerous smal! spines on the ossicles of the division series and 

 arm bases; cirri about XX, 25 — 30; 10 — 12 arms about 50 mm. 

 long; IIBr series 4 (3 + 4) (near A se en si on I si and, south 



Atlantic; 756 Me tres) multispina 



dorsal surface of the ossicles of the division series and arm bases with 

 very few or no spines 



d 1 cirri XX, 25; ossides of the IBr series and first two brachials with 

 sharp straight edges fringed with spines, and a \'v\v spines on the 

 dorsal surface; brachials smooth, without prominent distal ends; 

 segments of 1', with tufts of small spines along the distal border; 

 10 arms 30 mm. to 35 mm. long Ivermadec Islands; 1 1 34 



Metres) echinata 



d cirri X, 21; ossicles of the IBr series and first two brachials with 

 no spines 011 the dorsal surface; brachials with prominent distal 

 boniers bearing very fine spines; segments of I', with a few very 

 fine spinules; to arms probably about 35 mm. long; Canary 



Islands; 1 , Metres) omissa 



b at least 34 (from 34 to rru » se ^ments 



cirri arranged, more or less regularly, in 15 crowded columns, three 

 in each radial area <>i 1 trodorsal; the radial areas of the centro- 



dorsal are not differentia 



d r\ large; arm-, 175 mm. long; ossirles of the [Br series and 



achials as far as the ond syzygy fringed on the proximal and 



