THYSANOPODA. 207 



Sta. 4676. Dec. 5, 1904. Lat.. 14° 2S.9' S., long. 81° 24' W. 300 fms. to surfafc. 1 .specimen. 



Sta. 4679. Dec. 7,1904. Lat. 17° 26.4' S., long. S6° 46.5' W. 300 fms. to surface. 1 .specimen. 



Sta. 4681. Dec. 8,1904. Lat. 18° 47.1' S., long. 89° 26' \V. 300 fms. to surface. 2 specimens. 



Sta. 4683. Dec. 9,1904. Lat. 20° 2.4' S., long. 91° .52.5' \V. 300 fms. to surface. 2 .specimens. 



Sta. 4707. Dec. 29, 1904. Lat. 12° 33.2' S., long. 97° 42' \V. 300 fms. to surface. 1 specimen. 



Sta. 4722. Jan. 16, 1905. Lat. 9° 31' S., long. 106° 30.5' \V. 300 fms. to surface. 1 specimen. 



Sta. 4740. Feb. 11, 1905. Lat. 9° 2.1' S., long. 123° 20.1' W. 300 fms. to surface. 3 specimens. 



Distribution. — According to the literature this' species is Iviiown fmin the 

 Atlantic, where it extends nortliwui-tls to Lat. 46° 15' N. and soutliwai'ds to a 

 ]ihice off Tristan da C'linha; al.so from the Bay of Bengal, the Intlian .\rchi- 

 pelago, and South of Australia. 



It is a true bathypelagic species and this explains perhaps that among the 

 twelve specimens from seven Stations in the East Pacific only a single specimen 

 (from Sta. 4707) seems to be really adult. 



THYSANOPODA H. Milne Edward.s (18.30). 



The material of this large and somewhat difficult genus is very rich, com- 

 prising nine species; a young specimen, which is very far from adult though not 

 small, I have with some doiiljt referred to T. cornuta lUig, of wliicli a much 

 larger specimen is at hand. Only two valid species of this genus are not found 

 in the collection, but l)oth are known only from the North Atlantic' 



The maxillulae differ much from each other in various species, affording 

 excellent specific characters, especially characters for cjuite small gi'oups of 

 species. In a couple of species the outer lamella from their first lobe, the 

 "pseudexopod," is somewhat small, at most .sUghtly overreaching the outer 

 margin of third joint, while in most species the pseudexopod is of moderate 

 size or \'ery large, with its greater part reaching beyond the outer margin of 

 third joint; furthermore the fourth joint, the pal]:), differs extremely as to 

 length and breadth in various species. For these reasons I ha\e gi\'en figures 

 of the maxillulae of most species. — The maxillae of various species differ 

 generally but little in shape, and therefore it has been deemetl unnecessary to 

 figure more than the maxilla of a single species. 



Group a. Carapace witluuil anij distinct cervical groove. Ma.riUuhie wilJi 

 the pseudexopod from niodcratrlij titrijc to very large, with at Icai^l ahnn.^t their h<df 

 situated beyond the outer margin of third joint, ami with the palp at mast moder- 

 ately long and somewhat ovcrrcacliing tin' third joint. Si.rth abdominal .segnietit 

 longer than the fifth. 



' Thijsanopoda megalops lUig as rc-estahlished by lliat author in .July, 1911, on a specimen from 

 the Indian Ocean is certainly a young and most probably the young of T. i;irnjiii II, .1. 11. 



