42 TREMATODES OF THE NORTHUMBERLAND COAST 



regard this as strong evidence that the mouth is a natural 

 habitat for Derogenes varicus. 



An ectoparasitic Trematode is known that Hves attached 

 to a Copepod parasitic on a fish, i.e., Udonella caligorum, 

 Johnson, which lives on the ovisacs and posterior part of 

 Caligus airtus on the Cod and other Gadoids*; but this is, so 

 far as I know, the first time that a Copepod has been found 

 parasitic on a Trematode.. Unfortunately the specimen is 

 greatly spoiled by the preserving agent, and only very rough 

 sketches were made of the living animal. It appears to be a 

 new species, possibly a new genus, probably nearly allied to 

 Ergasihis\, as Mr. T. Scott kindly suggested to me from a 

 sketch submitted to him. The hooks on the head (the 

 antennae) are much thicker and heavier in my specimen. Only 

 one egg-bag was to be seen, and it was full of well developed 

 eggs of a purplish hue. I give a drawing oi Derogenes varicus 

 (fig. i) to compare with figures 2 and 3. It is to be hoped 

 that further specimens may be found to establish this new 

 species (or genus) on a firm foundation. So far much search 

 . has produced no more specimens. 



Steringophorus ovacutus, n. sp. (Plate III., figs. 4-5). — 

 I shall conclude with a description (unfortunately not quite 

 complete) of a new species of Trematode belonging to the 

 genus Steringophorus, Odhner. Only one species of this genus 

 is, I believe, known, and I am pleased to be able to add a 

 second, which I have named Steringophorus ovacutus. This 

 Trematode is rare. It was found in the intestine of the Long 

 Rough Dab Hippoglossus limandoides (June and November, 

 1907); only four specimens were found, and each time they 

 occurred singly. It closely resembles *S'./?/r«^(fr(01ss.) When 

 alive it is bright red, and often appears pear-shaped owing to 

 the head end being stretched out. The colour vanishes 

 immediately after death, which takes place almost directly the 

 worm is taken from the intestine ; it then has a pale yellow 



* Scott, T., loth Annual Report of the Fisheries Board for Scotland, 1901, p. 144. 

 t Scott, T., Op. cifc., p. 122, 



