ENTOMOSTRACA OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 303 



the second joint is of a broadly ovate form, its greatest width being equal to about 

 half the length, and it carries four (or five) short setae round the lower part of the 

 outer margin and apex, as shown in the drawing (fig. 30). 



Caudal rami short. 



Habitat. Scotia Bay, South Orkneys; collected in June 1903; Station 325, 

 60 43' 42" S., 44 38' 33" W. No males observed. 



Remarks. As already stated, this species has a somewhat close resemblance to 

 Tisbe minor (T. Scott), first described in the Annals of Scottish Natural History in 

 October 1896, from specimens obtained in the Firth of Clyde. The same species has 

 also been recorded from Norway by Professor G. 0. SARS, and it was one of the 

 Harpactids discovered by Dr BRUCE in Franz Josef Land. But the Antarctic form, 

 though closely resembling the northern species referred to, may be readily distinguished 

 from it by the broadly ovate form of the second joint of the last pair of thoracic legs. 



The genus Tisbe, as Professor G. 0. SARS remarks, " seems to be represented in all 

 parts of the oceans," and he has " even found one or two species of this genus in the 

 Caspian Sea." : Dr GIKSBRECHT obtained two species belonging to the Idygea in the 

 collections brought home from the Antarctic by the Belgica in 1899;t both these 

 species, however, differ in several respects from those observed in the material collected 

 by the Scotia ; and they differ especially in the structure of the first and fifth pairs of 

 thoracic legs. I am also unable to identify the Scotia species with either of those 

 recorded by Dr BRADY in his account of the Copepoda-Harpacticoida of the Deutsche 

 Siidpolar Expedition, pp. 5 GO, 5G1.J 



Tisbe gracilipes, new species. (PI. I. figs. 23-29.) 



Female. The female of this species is somewhat like that of Tisbe gracilis (T. 

 Scott) in its general form, being elongated and rather slender. 



The antennules are tolerably elongated ; the second joint is rather longer than the 

 third, which, in its turn, is about one and a half times the length of the fourth joint. 

 The three following joints are small, while the end one is equal to the two preceding 

 joints combined (fig. 23). 



Antennae moderately slender, the outer ramus four-jointed and rather longer than 

 the penultimate joint of the inner ramus (fig. 24). The mandibles and other mouth 

 organs are somewhat similar to those in Tisbe gracilis. 



The thoracic legs are also somewhat similar to those in the species mentioned, but 

 in the first pair, the second joint of the inner ramus is proportionally more elongated, 

 being fully one and a half times the length of the first joint. The outer ramus scarcely 

 reaches to the end of the first joint of the inner one (fig. 26). In the fourth pair, the 



* Crustacea of Norway, vol. v. p. 88 (1905). 



t Resultats du Voyage du s.y. " Belgica" " Copepoda," von Dr W. Giesbrecht, p. 38 (1902). 



I Deutsche Siidpolar Expeil., 1901-1903: "Uber die Copepoden der Stiimme Harpacticoidii, Cyclopoid;i," etc. 

 (1910). 



(HOY. 8OC. EDIN. TKANS., VOL. XLVIII., 549.) 



