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. Echinorhynchus acus, Rudolphi, Entoz. Hist. Nat., 

 Vol. II., p. 279. 



1850. Echinorhynchus acus, Dies., Syst. Helminth., Vol. II., 

 p. 39. 



Many examples of this Echinorhynchus were observed in the intestine of 

 a large cod-fish captured in the Moray Firth in June 1897, and though 

 frequently 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 Echinorhynchus acus are said to include a number 

 of different kinds of fishes such as Coitus 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 thai it 

 is probably only a variety or a slightly immature form of that species. 



Echinorhynchus agilis, Rudolphi. PI. IV., figs. 1-2. 



1819. Echinorhynchus agilis, Rud., Entozoorum, Synopsis 67 



et 316. 

 1850. Echinorhynchus agilis, Diesing, Syst. Helminth., 



Vol. II., p. 35. 



Diesing's definition of this species is as follows : — " Proboscis clavata, 

 uncinorum seriebus 3. Collum brevissimum inerme. Corpus utrinque 

 attenuatum, densissime iransversim striatum. Longit. 2-3." And he 

 mentions as the hosts of this entozoon Mugil cephalus, captured at Spezia 

 (Gulf of Getioa), and Mugil labeo, captured at Remi. This description 

 by Diesing applys fairly well to an Echinorhynchus observed in the 

 intestine of a Grey Mullet, Mugil 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 E. proteus in a number of American fishes. 



