DR. T. S. COBBOLD ON ENTOZOA. 167 



occurrence of a cestoid entozoon. This species of Bothriocephalus I have not seen ; but 

 in a specimen of the above-named fish its place was supplied, as it were, by two other 

 worms — the Disfoma fitimim (figs. 6, 7, 8), hitherto observed in the Ling and Gadus medi- 

 terraneus, and the common F'daria piscium, which is especially abundant in the Cod-tribe. 

 So far as I am aware, the Distoma fulvum has not yet been figui'ed under that name, but 

 after a careful investigation I am satisfied that it is identical with the D. simplex of 

 Rudolphi and Fasciola BramcB of Muller*. Dujardin, after giving the specific characters 

 of D. simplex, appends an account of two imnamed trematodes which he fo\md in a 

 specimen of Gadus quinquecirratus from the coast of Brittany ; these also appear to me 

 to be one and the same species, and I think he would have been justified in considering 

 them as merely altered forms of D. simplex or I), fulvum. Dujardin moreover makes 

 2). simiplex synonymous with the Fasciola JEgleJini of Muller and the D. Wachnice, first 

 described by Tilesiust. After consulting the figures and descriptions of these authors, I 

 consider D. Wachnice to be the original representative both of D. simiplex and B. fulvvm, 

 but I believe F. jEglefiid may be properly regarded as a distinct species. The living speci- 

 mens of D. fulvum examined by me alternately elongated and contracted themselves very 

 vigorously, thus varying the length of the body between the twelfth and fortieth part 

 of an inch. In this way the neck sometimes became extremely attenuated, contrasting 

 strongly with the large and prominent ventral sucker. Under a half-inch lens, the largest 

 specimen, as now preserved, exhibits the intromittent organ everted and the convoluted 

 uterine tube crowded with ova. 



The only entozoon I have observed in the viviparous Blenny is a single specimen of 

 Ascaris aitcta, R. It was coiled in a cyst beneath the peritoneal surface of the liver, the 

 gland being otherwise diseased. In an example of Blennius pholis, four specimens of 

 Echinorhynchus tereticollis, R., were obtained from the intestine, in different stages of 

 development. The largest exhibited a bulging of the cuticle near the middle of the body, 

 probably the result of injury. 



Coitus bubalis. — Several were examined and only one found infested — that by a single 

 tape-worm, which occupied the intestine immediately below the pancreatic caeca. This 

 entozoon, long known to inhabit Cottus scorpius, and by Muller termed Tania Scorpii, 

 has been more fully described by Leuckart, Eschricht, and Van Beneden, under the better 

 title of Bothriocephalus jyunctatus. The extreme transparency of this worm, when alive, 

 produced, dui-rng its active movements, very puzzling appearances, and had I not pre- 

 viously entertained the persuasion that all tape-worms were destitute of a true digestive 

 tube and buccal cavity, I should have felt entitled to aflirm, that this species at least was 

 provided mth a continuous alimentary canal. The anterior cephalic segment, while 

 extended, gi-eatly exceeded in length each of the ten or twelve succeeding segments, and 

 when contracted appeared rather broader. Miiller's figure gives an idea of considerable 

 disparity in this respect, but in other particiilars the specific resemblances were at once 

 recognized. Toward the lower part of the so-called neck, the joints exhibited at the lateral 

 margins indications of division, which became gi-adually more defined towards the tail. 



* Zoologia Danica, torn. i. p. 33. pi. 30. fig. 6. 



t M^m. de I'Acad. des Sciences de St. P^tersb. torn. ii. p. 363. tab. 19. figs. 8-10. 



y2 



