ELOOD-PAEASITES OF FISHES OCCURRING AT ROVIGNO. 133 



which there are six to eight, of varying prominence and 

 depth (figs. 29, 31). In other cases the membrane appears 

 as an extensive flap or fin, with a slightly wavy bordei', and 

 widest about the middle of the body (fig. 30). We think the 

 difference between these two aspects is more apparent than 

 real, due to a large extent to the flattening out of the parasite 

 on the slide, in the second case. On the other hand, in the few 

 individuals we have observed on " wet" films the membrane 

 appears narrow and inconspicuous (cf. figs. 51, 65), and we 

 should certainly be inclined to say it had undergone some 

 shrinkage here. 



One or two remarks which we have to make upon the 

 nuclear structure may be deferred until we consider the 

 trypanosome-nucleus generally in the second part of this 

 paper. The only detail with regard to the general cytoplasm 

 that requires mention is the occurrence in certain cases of 

 numerous granules. These granules are only noticeable in 

 parasites on Giemsa-stained smears. In some individuals 

 (fig. 31) the cytoplasm is quite free from them ; in others 

 there are a certain number of small dark granules, chiefly in 

 that part of the body lying between the two nuclei. The 

 flattened-out individuals, however, are rendered conspicuous 

 by the presence of numbers of lai^ge granules, apparently 

 occupying most of the body (fig. 30). Moreover, many are 

 seen lying apparently in the membrane. These granules 

 stain a purple colour of a somewhat deeper tint than the 

 lilac of the cytoplasm. 



The trypanosome from Trigla corax, to which Neumann 

 has given (I.e.) the specific name of triglae, is described 

 very briefly and without any figures. According to Neumann's 

 account the parasite is of a different type of form from that 

 which we have above described. Its total length is about the 

 same, namely, 60 fx, but the free flagellum is rather longer, 

 being 15 fi. The chief difference, however, is in the breadth, 

 which appears to be much greater. Neumann gives the 

 width of the body as 8 /x and that of the membrane as 4 [i, 

 the entire width being thus 12 fi as compared with an average 



