DR. T. S. COBBOLD ON ENTOZOA.. 157 
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 Distoma fulvum (figs. 6, 7, 8), hitherto observed in the Ling and Gadus medi- 
terrameus, and the common Filaria piscium, which is especially abundant in the Cod-tribe. 
So far as I am aware, the Distoma fulvum has not yet been figured under that name, but 
after a careful investigation I am satisfied that it is identical with the D. simplex of 
Rudolphi and Fasciola Bramæ of Müller*. Dujardin, after giving the specific characters 
of D. simplex, appends an account of two unnamed trematodes which he found 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 D. fulvum. Dujardin moreover makes 
D. simplex synonymous with the Fasciola ZEglefini of Müller and the D. Wachnie, first 
described by Tilesiust. After consulting the figures and descriptions of these authors, I 
consider D. Wachnie to be the original representative both of D. simplex and D. fulvum, 
but I believe F. Zglefini 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 aucta, 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. 
Cottus bubalis.—Several were examined and only one found infested—that by a single 
tape-worm, which occupied the intestine immediately below the pancreatic cæca. This 
entozoon, long known to inhabit Cottus scorpius, and by Miller termed Tenia Scorpii, 
has been more fully described by Leuckart, Eschricht, and Van Beneden, under the better 
title of Bothriocephalus punctatus. The extreme transparency of this worm, when alive, 
produced, during its active movements, very puzzling appearances, and had I not m- 
viously entertained the persuasion that all tape-worms were destitute of a true digestive 
tube and buccal cavity, I should have felt entitled to affirm, that this species at least was 
provided with a continuous alimentary canal. The anterior cephalie segment, while 
- extended, greatly exceeded in length each of the ten or twelve succeeding segments, and 
when contracted appeared rather broader. Müller’s figure gives an idea of considerable 
disparity in this respect, but in other particulars 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 gradually more defined towards the tail. 
* Zoologia Danica, tom. i. p. 33. pl. 30. fig. 6. 
+ Mém. de l’Acad. des Sciences de St. Pétersb. tom. ii. p. 363. tab. 19. figs. 8-10. ^ 
: > 
