THYSANOPODA. 207 



Sta. 4676. Dec. 5, 1904. Lat. 14° 28.0' S., long. 81° 24' W. .WO fms. to surface. 1 specimen. 



Sta. 4679. Dec. 7, 1904. Lat. 17° 20.4' S., long. 86° 46..5' \V. :i()() fnis. to suifacc. 1 specimen. 



Sta. 4681. Dec. 8,1904. Lat. 18° 47.1' S., long. 89° 26' W. ;i()() fms. to .surface. 2 specimens. 



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



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



Sta. 4722. Jan. 16, 1905. Lat. 9° 31' S., long. 106° 30.5' W. 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 known from the 

 Atlantic, where it extends northwards to Lat. 46° 15' N. and southwards to a 

 place off Tristan da Cunha; also from the Bay of Bengal, the Indian Archi- 

 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 Edwards (1830). 



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

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

 small, I have with some doubt referred to T. cornuta lUig, of which a much 

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

 in the collection, but both are known only from the North Atlantic' 



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

 •excellent specific characters, especially characters for quite small groups of 

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

 "pseudexopod," is somewhat small, at most shghtly 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; fm'thermore the fourth joint, the palp, differs extremely as to 

 length and breadth in various species. For these reasons I have given figures 

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

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

 figure more than the maxilla of a single species. 



Group a. Carapace without any distinct cervical groove. Maxillulae with 

 the pseudexopod from moderately large to very large, with at least almost their half 

 situated beyond the outer margin of third Joint, and with the palp at most moder- 

 ately long and somewhat overreaching the third joint. Sixth abdominal segment 

 longer than the fifth. 



' ThysanOpoda megaloips lUig as re-established by that author in .luly, 1911, on a specimen from 

 the Indian Ocean is certainly a young and most probablj- the young of T. egrerjUi H. J. H. 



