.studies on marine Ostracods 265 



Alfrkd Ramsch, in his work of 1906. p. 384, rejects O. G. Costa's assumption that we 

 have to deal with parasitism in the case quoted above, put forward by 0. G. Costa*. He points 

 out that he had himself often come across different forms of large Ostracods in Pagdlus 

 both beneatli the gill-cover and in the stomach; all the specimens so found were, however, 

 dead. He writes 1. c. : ,,Sie dienen den Fischen zur Nahrung und gelangen mit dem Atemwasser 

 an die Kiemen oder finden sich gelegentlich im Darmtraktus. Ihr angebliches Vorkommen 

 in der Abdominalhohle mochte ich wohl als eine zufaUige Erscheinung auffassen." 



This idea of A. Ramsch's seems to be incorrect. It is true that 0. G. CosTA does not give 

 anv information as to whether the specimens found by him were alive or not at the time they 

 were caught, but all the evidence is in favour of their being parasitic specimens. Of course 

 this does not prevent O. G. Costa's theory that we are concerned with an exclusively 

 parasitic species from being incorrect. 



From the cases put forward above one may perhaps draw the conclusion that within 

 the sub-genus Vargula there exists a certain ,, tendency" towards a parasitic life. One may 

 perhaps say that it is the first groping attempts towards the carrying out of this tendency that 

 have been just brought to our notice. 



It may be objected here that the word , .parasitism" ought not to be used for these cases. This 

 form of life ought rather perhaps to be called ,,conimensalisni", as has already been done by A. BRIAN. 

 As a matter of fact we are probably dealing with a case which is on the boundary between these two 

 phenomena; both commensalism and real parasitism certainly exist; the question as to which 

 term is to be used before the problem has been investigated more closely is of minor importance. 



If we try to determine this species according to the scheme of the genus Cypridina given Relation to 

 by G. W. MOLLER, 1912, p. 10, we find as follows: The furca has nine claws, the thii-d of which ^- ^^^'^ «""'^^">«- 

 is more than half the length of the second; the rostral incisur of the shell is well developed; the 

 length of the shell is less than 4 mm.; the upper lip has two large tusk-like processes — ,,Mit 

 2 hauerartigen Fortsatzen hinter den anderen Driisenmiindungen" ; the second and fourth 

 furcal claws are joined to the lamina. — It is, however, not Cypridina norvegica we arrive at — 

 as, on account of the incomplete description of this species, it could not be included in this exami- 

 nation scheme — but an antarctic species, Cypridina antarctica G. W. MtJLLER. 



A close investigation of the description of the last-mentioned species — G. W. MOller, 

 1908, p. 84 — shows that we are dealing with a form closely allied to C. (Vargula) norvegica. — 

 In order to be able to undertake a more detailed comparison between these two forms I wrote 

 to Professor G. W. MUller, who was kind enough to send me a sexually mature female of the 

 antarctic form and it is on this material that the supplementary description given below is based. 



Habitat: — Coast of Norway: 



Lofoten Islands: 1 mature male, 2 mature females and 3 juvenes; coll. unlfnown; 

 R. M. S. 155. Skarnsimd, Trondhjem Fjord; in a specimen of Etmopterus spinax (Linxe): 

 5 mature males, 12 mature females and 8 juvenes; coll. Hj. OstergreN; R, M. S. 156 and 157. 



• „VolllvOmmen im Irrthum ist jedoch Costa, wenii er behauplol, dali Cypridina mediterranea parasitisch in 

 Fisohpn lebe." 



Zoloog. bldras, TJppsuln. SiippK-Bil. T. 34 



