ON THE ANATOMY OF A MARINE 



OSTRACOD, CYPRIDINA (DOLORIA) 



LEVIS SKOGSBERG 



By H. Graham Cannon, ScD. 



Professor of Zoology in the University of Sheffield 



(Plates VI and VII, text-figs. 1-12) 



INTRODUCTION 



IN 1926, I received from Dr Kemp a tube containing about thirty specimens of an 

 Ostracod, most of which were carrying embryos. I identified them as a Cypridinid 

 described by Skogsberg (1920, p. 225) from South Georgia and placed by him in a 

 sub-genus Doloria as Cypridina (Doloria) levis. I shall refer to them as Doloria. 



They had been specially fixed for me in alcoholic Bouin (Dubosq-Brasil). I attempted 

 to section them, and at first failed. The ribbon of sections refused to stick on the slide. 

 In this way all except eight specimens were destroyed. These, as a last resort, I placed 

 in very strong acid alcohol — about i part of cone. HCl to 5 of 70 per cent alcohol — for 

 three days. They then sectioned perfectly, and on staining them in Mallory's triple 

 stain I found them to be extraordinarily well fixed. The state of fixation can be seen 

 from Plate VII. I have since treated British marine Ostracods to the same technique 

 but the results have been very poor. 



Since the internal anatomy of Cypridinids and, in fact, of Ostracods generally is very 

 incompletely known, I decided to work out the main systems of organs, and the fol- 

 lowing paper is the result of these investigations. 



The systems described are enumerated on the opposite page. I have not described 

 the genital system, as my material was incomplete for this purpose. The labral glands 

 I omitted, as these have already been described many times in detail. The observa- 

 tions are, of necessity, mainly descriptive and will form a basis for comparative work 

 when specimens of Ostracods from other groups are obtained sufficiently well fixed 

 for anatomical work. 



I had a further supply of material which, however, had been fixed in alcohol. While 

 sections of these specimens were of no use for studying the details of anatomy, they 

 were useful for skeletal preparations and for confirming observations on my well-fixed 

 material, especially details of musculature. 



The exoskeleton and part of the endoskeleton were studied from preparations treated 

 with potash. I used the method which I have previously described (1927, p. 355) in 

 order to obtain sagittal or frontal halves or slices of specimens. These I treated with 

 potash and mounted in glycerine jelly. 



