SECTION IV 

 OSTRACODA 



FROM ELEVATED DEPOSITS ON THE SLOPES OF MOUNT EREBUS, 

 BETWEEN CAPE ROYDS AND CAPE BARNE 



GENERAL REMARKS ON THE COLLECTION 



All the Ostracoda here recorded were obtained from some moderately fine washings 

 floated from the molluscan sittings examined by Mr. Chas. Hedley. The material 

 was obtained from the deposit found 160 feet up the slopes of Mount Erebus, about 

 one mile and a half from Cape Royds towards Cape Barne. The specimens are very 

 abundant, but belong to few species. They range from 20 fathoms in the case of 

 Cytherura costdlata to 1425 fathoms in Bairdia victrix. The occurrence of B. victrix 

 tends to show a limiting depth for the deposit of rather more than 100 fathoms, since 

 the least depth for that species hitherto recorded is 120 fathoms. There are eight 

 species in this series, two of which are new forms. They belong to the genera Bairdia, 

 Cythere, Loxoconclia, Xestoleberis, and Cytherura. In point of abundance Cythere 

 parallelogramma comes first, the next in order being C. polytrema and C. normani ; 

 the remainder being somewhat, or altogether, rare. All the previously described 

 species are either known from, or allied to forms of, the Southern Ocean. 



DESCRIPTION OF THE OSTRACODA 



Family— BAIRDIIDiE 



Genus — Bairdia, McCoy, 1844 



Bairdia victrix, G. S. Brady (Plate VI, Fig. 1) 



Bairdia victrix, G. S. Brady 1867, Les Fonds de la Mer, vol. i, p. 152, PI. XVIII 

 Figs. 17, 18. Idem, 1880, Bep. Chall, Zool., vol. i, Pt. Ill, p. 56, PI. X, Figs. 5a-5d. ' 



Some remarkably fine valves occur in the present series. The species has some 

 resemblance to B. amygdaloides, which is found as far south as Bass Strait, but the 

 posterior extremity is rounded off instead of tapering to a point. It has a wide range : 

 from the West Indies to Kerguelen Island, and thence to Sydney. It inhabits 

 " chiefly water of a considerable depth " (G. S. B.). 



Family— CYTHERIDiE 



Genus— Cythere, Muller, 1785 



Cythere foveolata, G. S. Brady 



(For references see previous Report) 



Two valves of this species occur here. It has already been noted from the upthrust 

 muds south-east of Mount Larsen, in which deposit it was rather abundant. 



" 49 G 



