150 DE. w. c. m'intosii on the food and 



as above mentioned, is not the case with the salmon from the Tay, 

 in which this parasite is rarely wanting. The description of the 

 foregoing authors leaves little to be added, further than that Ru- 

 dolphi is correct in stating that there is no anus as described by 

 Miiller. Detached and solitary ova frequently occurred in all por- 

 tions of the intestine and caeca. In some specimens, bodies that 

 seemed to be spermatozoa-cells were seen, in constant motion 

 within tubes. When the Distomata are put into water, they wriggle 

 and lengthen themselves, and the ventral disc may be seen occa- 

 sionally tinged with blood. In the duodenum ©f one fish was a 

 remarkable Distoma, which appeared rather to be two in con- 

 gress, but yet may be a malformation, since one oral sucker only 

 could be found, and each half diifered somewhat from the body of 

 an ordinary Distoma. 



A single specimen only of another species of Distoma {D. tere- 

 ticolle), of an elongated form, occurred in the intestine of a salmon. 



In the oesophagus of a salmon a peculiar flask-shaped body was 

 met with. It equalled in size a full-grown Distoma varicum, was 

 of a yellow colour, and possessed two dark-brown patches, one at 

 the broad end, and the other an elongated lateral one. The 

 general body of the structure was filled with cells and granules, 

 while the dark patches were made up of the dark-brown cells or 

 masses, and some of the latter were of an elongated form. The 

 contained pale cells and granules floated readily out through any 

 fissure. Whether it is a parasitic structure pertaining to the 

 salmon or some other fish I am unable to state, farther than that 

 it once occurred in the stomach of the former. 



I found a single specimen of TetrarhyncTius appendiculatus 

 (Hud.) when washing the mucous surface of the stomach of a sal- 

 mon. On this there was a little eminence having a minute aper- 

 ture at the summit, which when pressed gave exit to a small white 

 body — after the manner of the parasites of the human skin, and 

 the part extruded was the posterior elongated body shown in 

 the figure *. When a section divided the eminence, the creature 

 firmly adhered by its anterior hooks. On removal, it progressed 

 leech-fashion by successive waves of its soft white body, adhering 

 by either end at pleasure. The anterior or larger portion of the 

 body was intensely white, the posterior appendage less so. When 

 moving, its body assumed various shapes, now like a thick round 

 jar, or again like an elongated flask, with numerous longitudinal 

 striae on its external surface. The body of the Tetrarhyuchus was 



* Eudolphi, tab. 7. fig. 10. 



