188 DR WALTER M. TATTERSALL ON 



first joint of the antennular peduncle. This lobe in E. spinifera, extends right across 

 the peduncle and has its anterior margin irregularly digitate. In the present specimen, 

 the lobe does not stretch right across the peduncle, and the extremity is bifid. It 

 thus agrees, in this respect, with E. longirostris. The copulatory organs on the first 

 pleopods, however, agree almost exactly with those figured by SARS for E. spinifera. 

 HANSEN has not, up till now, described the male of E. longirostris, so I am unable to 

 compare my specimen from this point of view.* HANSEN says that E. longirostris is 

 closely related to E. spinifera, and is only distinguished by the antennular lobe. On 

 that character, therefore, I refer my specimen to that species. 



E. longirostris is known, at present, only from the Antarctic Ocean to the south 

 of the Falkland Islands and in the neighbourhood of South Georgia. The present record, 

 therefore, is the most northerly one yet known for the species. 



Genus Thysanoessa, Brandt. 

 Thysanoessa macrura, G. 0. Sars. 



T. macrura, G. O. Sars, 1885a. 



Scotia. 



Station 319, lat. 61 05' S., long. 43 20' W., 214 fathoms. One female, 



14 mm. 

 Station 414, lat. 71 50' S., long. 23 30' W., vertical net, 0-1000 fathoms. 



One female, 28 mm. 



If the evidence of the antennular flagellum be accepted, the smaller of these two 

 specimens is correctly referred to this species, since it is distinctly shorter than the 

 two distal joints of the peduncle. The larger specimen seems clearly to belong to 

 T. macrura. The species has a circumpolar distribution in Antarctic waters. 



Thysanoessa gregaria, G. 0. Sars. 



T. gregaria, G. O. Sars, 1885a. 



Scotia. 



Station 98, lat. 34 02' S., long. 49 07' W., tow-net. One. 

 Station 458, lat. 42 57' S., long. 8 13' W., tow-net. Twenty-six. 



Discovery. 



Lat. 37 47' S., long. 3 59' E. Two. 



A post-larval specimen of the genus Thysanoessa taken by the Scotia at Station 

 137, lat. 57 42' S., long. 46 33' W., cannot be referred to its adult species. It may 

 belong to T. gregaria or to T. vicina. Hansen (1911). 



* Sri- note.', j). 204. In this paper HANSEN describes and figures the copulatory organs of the male of this species, and 

 points out minor dillt-rtnces from those of E. spinifera. 



(ROY. soc. EDIN. TRANS., VOL. XLIX., 878.) 



