BLOOD-PARASITES Ob' FISHES OCCURRING AT ROVIGNO. 113 



Observations on certain Blood-parasites of Pishes 

 occurring at Rovigno. 



By 

 Prof. 'E. A. iniiicliin, lYI.A., and H. JTI. ll^'oodcock, D.Sc. 



With Plates 8-10. 



The objects of this paper are twofold. The first is the 

 description of a hsemogregarine and a trypanosome occur- 

 ring in a species of Trigla (T. lineata), which is a common 

 gurnard in the Northern Adriatic. We are unaware of any 

 published observations of blood-parasites in this fish, and we 

 regard the hfemogregarine as a new species, for which we pro- 

 pose the name Haemogregarina rovignensis. Neumann, 

 in his recent account of haamatozoa of marine fishes at Naples 

 (15), mentions the occurrence of a trypanosome which he 

 names T. triglse in another species of Trigla, namely, T. 

 corax. It is not at all improbable that the trypanosome 

 we have found is the same species as that described by 

 Neumann ; we therefore do not propose to give it a new 

 specific name. 



The second object that we have in view is the comparison 

 of the minute structure of the nucleus of the above-named 

 haemogregarine with that of the trophonucleus of a trypano- 

 some. For this purpose, as the trypanosome of the Trigla 

 is very rare in our material, a trypanosome which occui-s in 

 much greater abundance in skates (Raia, sp.) in the 

 neighbourhood of Rovigno has been selected. This form 

 is most probably T. raise Lav. and Mesn. 



With regard to the technique, permanent preparations were 

 made according to both the principal methods in use. Smears 



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