DR. T. S. COBBOLD ON ENTOZOA. 161 



(fig8. 30-32). It is not unlikely that these are one and the same species, seeing that the 

 principal difference, according to Dujardin, consists in the colour of the body and in the 

 relative size of the ventral sucker. A living Distoma varies much in form during con- 

 traction, and the same worm will present appearances when preserved very unlike those 

 seen when it was fresh. I have found this to be the case especially in the entozoon 

 under consideration, the ventral sucker presenting, during life, a most unusual breadth. 

 The oral sucker was comparatively small ; the simple gastric caeca, uterine tubes and con- 

 tractile vesicle being severally large and conspicuous. 



Haia hatis. Sijngnathus acus. — Of Entozoa infesting the former, I have only to notice 

 the extreme abundance of JSothriocephalus coronatus (R.) occupying the chambers of the 

 spiral intestine. Under an amplification of 400 diameters, the advanced ova exhibit a 

 well-developed Scolex, provided with rudimentary booklets and sclerous particles. In 

 the common Pipe-fish I have found several specimens of Filaria piscium. 



Lophim piscatorius. — The voracious habits of the Angler guarantee the presence of a 

 variety of worms, and, vrith the exception of Orthagorisctis, no fish is perhaps more 

 copiously infested. A specimen, dissected May 12, 1854, yielded tbi'ee species of Entozoa, 

 namely Ascaris rigida, Scolex polymorphus, and Distoma gracilescens. Most of the 

 nematode individuals were imbedded in folds of the peritoneum and mesentery, the other 

 kinds occupying the intestinal canal. Published descriptions of Distoma gracilescens 

 (figs. 33-37 inclusive) being few and imperfect, I offer the following notice of its more 

 obAdous characters : — Body of a pale brown colour, semitranspai'ent, one-sixth of an inch 

 long, flat, linear, beset all over with minute tubercular spines, those about the head being 

 more cogently developed ; anterior half somewhat narrower than the posterior ; oral sucker 

 oval, not quite terminal ; ventral sucker circular ; sheath of the penis large, and placed 

 immediately below the ventral cup; uterine tube broad and tortuous, occupying the 

 inferior half of the body ; vitelline organs consisting of two elongated, botiyoidal masses, 

 commencing a little below the oral sucker and passing down on either side of the neck ; 

 testes bulky, transparent, placed toward the lower and back part ; in front of these, two 

 smaller vesicular bodies, corresponding to the ovary and seminal vesicle ; contractile 

 vesicle very large, with thick muscular walls. 



Orthagorisciis mola. — I have dissected, in its entirety, but one specimen of this remark- 

 able fish. It was a very young individual, and was captured off Anstruther, on the coast 

 of Fife, September 6, 1856*. There were no Entozoa in the intestinal canal, but the 

 liver and retractor muscles of the anal fin contained several examples of the Gymnorhyn- 

 chus reptans of Rudolphi (figs. 38-46 inclusive). Professor Goodsii- has given an accurate 

 description of this cestode in the Edinbm-gh New Philosophical Joui-nal for 1841, under 

 the title of G. horridus, regarding it as a new species. If I may be allowed to differ, I 

 do not think the circumstance of Bremser's ha\ing omitted to notice the two lowermost 

 rows of exaggerated hooks on the proboscis, or his non-observance of the jointed condition 

 of the body, as sufiicient evidence that these characters were not present in his G. reptans. 



* Its dimensions were as follows : — Length from head to tail, 18 inches ; between tips of dorsal and anal fins, 26 inches ; 

 greatest depth of the body, 12 inches; length of pectoral fins, 2 inches and a half; width of the gill-aperture, 1 inch. 

 Two or three other individuals were taken a few weeks previously in the Firth of Forth. 



