244 Gr. A. and W. G. MacCallum, Four species of Microcotyle. 



extends forward to the male genital opening and in its anterior 

 portion seems to be practically filled with the spines which doubt- 

 less become recurved on the eversion of the penis. At the base of 

 this spiny portion there is a small cone shaped mass of red granules 

 whose function we cannot teil. 



Very little can be discerned with regard to the female genitalia. 

 There is a central somewhat coiled ovary the oviduct from which 

 receives the common duct from two lateral yolk ducts, biit there are 

 no eggs and the uteriis, although doubtless it runs straight forward 

 to the orifice described above, cannot be made out. 



It is perhaps wrong to describe a new species with so little 

 knowledge of the female genital apparatus but the character of the 

 penis and of the suckers seems so peculiar that the establishment 

 of a species seems justified and we hope to make the more detailed 

 study of the internal organs soon, when the worm is found in greater 

 numbers. Being a parasite of such a common fish as Roccus lineatus, 

 it is pretty sure to be found again before long. 



The suckers are all on muscular stalks: They are stout heavy 

 jawed and give the Impression of being supported by a much stronger 

 skeleton than that seen in M. eueides. pyragrapliorus or even pro- 

 portionately those in M. macroura. They are asymmetrically formed 

 and will be unterstood best by reference to the figures in one of 

 which the upper and lower halves of the suckers are represented 

 separately. In spite of what seems an entirely improbable arrange- 

 ment of the skeletal Clements, they all show precisely the same 

 structure. The upper half has three skeletal supports, a heavy curved 

 one on one side contrasting with the delicate curved ramus of the 

 other side, while the median support is only slightly curved and 

 turns inward at its end in the form of a tooth. The lower half 

 has the same arrangement at the sides, the lieavy ramus Standing 

 opposite that of the upper half but the median rod is replaced by 

 five large chitinous plates and flve small curved rodlets arranged 

 as shovvn in the sketch. These presumably strengthen greatly the 

 floor of the sucker. Viewed edgewise, the sucker presents strong 

 teeth which must be the product of the incurving of these rods for, 

 as in the other species, although one finds teeth on making a ver- 

 tical section of the sucker or viewing it edgewise, they cannot be 

 seen when the sucker is lying flat. The suckers measure 0,06 X 

 0,04 mm. 



