240 ^- ^- ä^"'^ W. G. MacCallum, 



tions frequently show wliat seems to be this band or plate actually 

 Crossing the cavity of the sucker free from its wall like tlie free 

 muscular bands that sometimes leap from one wall to the other of 

 the heart, but one cannot raake out this condition in the sucker 

 viewed as a whole. Occasionally, too, in sections the chitinous ends 

 of the median band seem to be denuded of their covering and to 

 project a short way almost like teeth into the orifice of the sucker^ 

 but this appears to be an artefact. They show, however, that in 

 addition to the coarse skeletal framework there are some fine chitin- 

 like filaments wliich course over the inner surface of the sucker 

 like wire gujTopes to further strengthen the whole structure. 



The suckers vary in size from 0,12 anteriorly to 0,33 mm and 

 diminish again at the tip to 0,04. 



Single examples of two other species of Microcotyle were found 

 on the gills of Roccus Uneatus and may be described here although 

 necessarily imperfectly because the material does not allow of a com- 

 plete study. 



3Iicrocotyle eueides, 



This form resembles in general Microcotijle pijmgraphorus from 

 the Pompano in possession of a broad wavy foot upon which the 

 suckers to the number of one hundred and seventy-six are arranged. 

 This foot is asymmetrically placed so that one side is rather longer 

 than the other as shown in the drawing (Fig. F). The body is very 

 delicate and thin and narrowed at each end. The total length is 

 about 8 mm. the greatest width of the body about 1,2 mm, while 

 the foot measures about 4,5 mm in width extending 1,5 mm on one 

 side of the median line and 3 mm on the other. There is a slight 

 widening of the anterior portion of the body about the genital pore 

 which is guarded by numerous spieules. Numerous pigmented cells 

 are scattered over the body especially abundantly among the lobules 

 of the vitellarium along the lateral margins. 



The mouth sac is provided as usual with two lateral imper- 

 forate suckers, the pharynx is small and inconspicuous. The in- 

 testinal coeca extend far back into the foot where they brauch and 

 become evident from their content of black granules. 



The ovary is large and coiled across the middle of the body. Its 

 oviduct evidently joins with the common duct from the vitellarium 

 to reach the straight uterus which then runs forward to the genital 

 pore. The yolk ducts are united both anteriorly and again just before 



