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CRUSTACEA. 



PART v.— OSTRACODA. 



BY R. W. BARNEY, B.A. 



(Lecturer in Biology, University of Hong Kong). 

 WITH SIX FIGURES IN THE TEXT. 



I.— INTRODUCTION. 



The material collected by the " Terra Nova " Expedition was received in fifty-oue tubes 

 of various sizes, some containing only one or two, others many hundreds of specimens. 

 It was entirely preserved in formalin. Many of the plankton jars were also examined, 

 and yielded ten additional species. Altogether twenty-two species, representing six 

 genera, have been identified. 



The examination of the collection was carried out in the lalwratory of Prof. 

 E. W. MacBride, F.R.S., in the Imperial College of Science and Technology, South 

 Kensington. 



II.— METHODS. 



The specimen was placed in four per cent, formalin in a watch glass, and the entire 

 animal removed from its shell by means of fine needles. To accomplish this, the 

 occlusor muscle was cut through on one side, and the valve thus freed was turned back. 

 Next the muscles attached along the hinge-line were cut, and lastly the occlusor muscle 

 on the other side. The shell was usually none the worse for this operation, and 

 frequently the shape of the rostral tooth and notch and occasionally the sculpture could 



2 D 



