118 Proceedings of the Royal Physical Society. 
IX.—Calliobdella nodulifera (Malm 1863).1_ By W. Harold Leigh-Sharpe, 
B.Sc. (Lond.). 
(With Plates.) 
(Read 23rd October 1916. MS. received 8th December 1916.) 
RECORD AND HaABITAT.—The material upon which the following observations ~ 
are based was sent to me, through the courtesy of Prof. L. A. L. King, by 
Mr Richard Elmhirst from the Scottish Marine Biological Association, 
Millport. It consisted of—(1) Two leeches taken in May 1915 off S.E. of 
Bute; (2) about three dozen leeches brought in at various times by 
fishermen; (3) two leeches caught by Mr Elmhirst, while trolling with 
“fly,” who noticed that the leeches were moving rapidly as though trying 
to leave the host fish as it was brought out of the water. These specimens 
were fixed in Schaudinn’s fluid, and from them most of the sections 
were cut. 
All these leeches were taken on the saithe or coalfish, Gadus carbonarius, 
Linn., from the head and gill-covers. I have also a specimen sent by 
Dr Bowman of Aberdeen, taken from a megrim, Lepidorhombus (Arnoglossus) 
(Zeugopterus) megastoma, caught in the Minch on 15th March 1910. Leeches 
are uncommon on flat-fish (except Hemibdella solee on the sole), but, as 
the megrim was caught in a trawl, there is a chance that the leech 
was derived from other fish taken at the same time. Unlike most of the 
leeches that have come under my observation, C. nodulifera appears to be 
catholic in its choice of hosts. Thus Malm originally records it from Gadus 
morrhua. Johansson found it on Gadus morrhua, G4. aeglefinus, G. merlangus, 
Merluccius vulgaris, Molva vulgaris, Raia batis, Hrppoglossus vulgaris, 
Anarrhichas lupus, and Trigla gurnardus. Olsson found it on Gadus 
morrhua, Molva vulgaris, Trigla gurnardus, Raia batis, Gadus virens, Sebastes 
norvegicus, Rava fullonica, Acanthias vulgaris and Chimera monstrosa. Nor 
does this exhaust the list. It is unnecessary, however, to continue since it is 
obvious that the host is here of but little physiological significance ; I have 
quoted these at length only to show that, apart from isolated instances in 
which single specimens have been recorded, the bulk of the evidence points 
to the fact that the Gadide are preferred. | 
1 References to previous papers :— 
1914. Calliobdella lophit: Parasitology, vii. 204. 
1916. Platybdella anarrhiche ; Parasitology, viii. 274. 
At the end of either of these papers will be found a full list of references to other authors 
hereinafter cited. 
