of the Fishery Board for Scotland. 87 
Echinorhynchus proteus, being a widely distributed and apparently a 
somewhat variable form, has been described under many different names. 
It has also been recorded from many kinds of fishes, both marine and 
freshwater ; at least over forty different kinds are mentioned as being the 
hosts of this worm.* 
Echinorhynchus acus, Rudolphi. Pl. IV., figs. 7-8. 
1°08. Hchinorhynchus acus, Rudolphi, Entoz. Hist. Nat., 
Wolo ap 279. 
1850. Hchinorhynchus acus, Dies., Syst. Helminth., Vol. IT, 
p. 3d. 
Many examples of this Hchinorhynchus were observed in the intestine of 
a large cod-fish captured in the Moray Firth in June 1897, and though 
frequentiy observed at other times and places, the species has not been 
represented so numerously as on that occasion. ‘They were found fairly 
numerous in the intestine of a saith captured recently in the nets of the 
salmon fishers working near the Laboratory. 
Although the hosts of Hchinorhynchus acus are said to include a number 
of different kinds of fishes such as Cottus scorpius, the Conger, the Angler- 
fish, and one or two kinds of flat-fishes, this parasite seems to be more 
frequently met with in Gadoids than in any other fishes captured off 
the coasts of Scotland. 
In this species the hooks with which the proboscis is armed are numerous 
and large ; they are arranged in close set and slightly oblique rows. There 
are about twenty hooks in a complete series extending once round the 
circumference, but scarcely half that number are in view at one time. Each 
hook is bent backwards at a sharp angle, as shown in the drawings (figs. 7 
and 8). The length of this species, as given by Diesing, is from one to 
three inches ; the largest I have noticed, however, scarcely exceeded 
50 millimeters in length. 
The Echinorhynchus represented by the drawings, figures 5 and 6 on 
Plate IV., was obtained in the intestine of a common Trout captured in 
Loch Tay in August 1901. The number of hooks in the series is rather 
less than in the specimen from the Gadoid—the number in view at one 
time being eight. But it so closely resembles Echinorhynchus acus that it 
is probably only a variety or a slightly immature form of that species. 
Echinorhynchus agilis, Rudolphi. Pl. IV., figs. 1-2. 
1819. Hchinorhynchus agilis, Rud., Entozoorum, Synopsis 67 
et 316. 
1850. ehinorhynchus agilis, Diesing, Syst. Helminth., 
Vol. IL., p. 35. 
Diesing’s definition of this species is as follows :—‘‘ Proboscis clavata, 
uncinorum seriebus 3. Collum brevissimum merme. Corpus utringue 
attenuatum, densissime transversim striatum. Longit. 2-3.” And he 
mentions as the hosts of this entozoon Mugil cephalus, captured at Spezia 
(Gulf of Genoa), and Mugil labeo, captured at Remi. This description 
by Diesing applys fairly well to an Hchinorhynchus observed in the 
intestine of a Grey Mullet, Mugzl chelo, captured in the nets of the salmon 
fishers near the Laboratory in June 1900, One of the specimens is repre- 
* Linton has also observed #. proteus in a number of American fishes. 
