NeiD and Rare Fossils. 35 



Brady records this species from many localities, chiefly in deep 

 water, as in the West Indies, ofi Sydney, and Papua. Egger notes 

 it from Kerguelen Island, and Table Bay, S. Africa. 



I have lately found this species in dredgings made by the F.I.S. 

 " Endeavour," from E. of Tasmania at 777 fathoms, and off South 

 Australia at 100 fathoms. 



It is very interesting to note that this species is one of the most 

 abundant in the Mallee fossil material, as it is in many deep-Avater 

 dredgings at the present day. It is, moreover, an almost restricted 

 southern form. The Mallee specimens frequently have their valves 

 united, pointing to tranquillity of the water during the deposition 

 of the calcareous Miocene ooze. 



Occurrence.— Bore 1, 215-244 feet (Janjukian). Bore 9, 256-263 

 feet; 315-325 feet (Kalimnan or Janjukian). Bore 10, 310-320 

 feet (Kalimnan or Janjukian). Bore 11, 219-260 feet; 260-265 

 feet (Kalimnan); 267-270 feet; 272-315 feet; 438-440 feet; 457- 

 458 feet (Janjukian). 



Cythere flexicostata, sp. nov. (Plate VII., Figs. 14a, h). 



Description. — Valve, seen from the side, elongate, pyriform; 

 broad anteriorly, with a deep flange-like border, highest in the 

 anterior third ; ventral and dorsal margins nearly parallel for some 

 distance, but tapering posteriorly to a blunt point; dorsal margin 

 convex, and interrupted by a short crest-like spine, ventral margin 

 straight; the posterior extremity is armed with a few ragged spines. 

 In edge view the valve is thickest in the posterior third, where it 

 terminates in a strong salient spine, falling abruptly and concavely 

 to the posterior, and gradually to the anterior, extremity. Surface 

 of valve ornamented with, six or seven longitudinal, sinuous costae, 

 which are more or less persistent from end to end of the valve; 

 they pass over the central boss or tubercle, and increase in strength 

 below and above the median area, being carried over on to the 

 anterior flange, and posteriorly take a sudden bend dorsally, pass- 

 ing steeply down to the blunt, spinous hind margin. Between 

 the costae there are faint pittings or excavations. 



Dimensions. — Length of valve, .92 mm.; height, .44 mm.; thick- 

 ness of carapace, about .6 mm. 



Observations. — So far as I can find, there is no described species 

 which shows a decided relationship to the above. Tlie general 

 form suggests a remote resemblance to the genus Bythocythere, 



4a 



