of the Fishery Board for Scotland. 8 5 



reveals certain interesting differences, which are fully described by 

 Professor van Beneden in the paper referred to, published in the Bulletin 

 of the Royal Academy of Belgium for 1889. 



In this paper he remarks that at first sight it suggested to him a 

 likeness to Tetrahothrmm maculatum, Olsson, a form previously recorded 

 from the same kind of fish, and therefore he gave the species the name of 

 Diplohothrium simile — the generic name Biplohothrium referring to the 

 peculiar arrangement of the bothria. He states further that "ce qui 

 caracterise surtout ce genre, c'est qu'il a, comme le precedent, une 

 cloison complete entire les deux couples of bothridies ; cette cloison 

 presente a son sommet quatre pieces qui semblent fournir des points 

 d'appui a la couche musculaire ; sous certains aspects, ce Cestode resemble 

 beaucoup au Cestode, dont nous venous de parler, et qui a ete decrit par 

 Olsson ; mais les organes qui lui ont fait donner le nom de Tetrabothrium 

 sont completement isoles, tandis que dans le Biplohothrium ils sont 

 reunis deux par deux ; a I'exterieur on croirait voir par moments quatre 

 orifices parfaitement separes, tandis qu'en realite il y'a, de chaque cote, 

 une separation qui ne s'etend pas jusqu'au bord des orifices." 



Genus Ahothrium, P. J. van Beneden (1870). 



Ahothrium rugosum (Goeze). 



1782. Taenia rugosa, T. A. S. Goeze, Versuch siner Naturg. der 

 Eingeweiderviirmer thierscher Korper, p. 411. Tab. xxxiii., 

 figs. 1-5. 



1808. Bothriocephalus rugosus, Rudolphi, Entoz. Hist. Nat., 

 Vol. III., p. 42. 



1850. Dihothrium rugosum, Diesing, Syst. Helminth, Vol. I., 

 p. 591. 



1870. Ahothrium gadi, van Beneden, Poissons des cotes de 

 Belgique p. 56, PI. V., fig. 14. 



This Cestode appears to be common in the sexually-mature stage in the 

 larger gadoids. Its head is invariably inserted in one of the c^cal tubes 

 and so intimately incorporated with its tissues as to have the appearance 

 of forming an integral part of the tube. For this reason, the attempts 

 made to remove the head of the worm from the tissues of the pyloric 

 cseca have usually ended in failure, and no satisfactory description of this 

 part of the worm has yet been published. 



The piercing of the wall of the pyloric cseca by the head of the Cestode 

 produces certain curious results ; the cascal tube becomes distorted some- 

 times to a considerable extent, nodular processes are formed, and 

 frequently, as remarked by Linton, a yellowish waxy deposit is formed 

 consisting of the degenerated tissue of the cseca. The worm, w^hich 

 extends from the csecal tube to the intestine, is often in the larger fishes 

 of considerable length ; specimens from such fishes sometimes reach to 

 twenty-five and thirty inches, but as, like most other Cestodes, they are 

 very contractile, the specimen that may, while living, stretch to thirty 

 inches will be found to be little more than half that length when 

 preserved, especially if the preservative be alcohol. Linton records a 

 specimen 65'5 millimeters in length, while Johnston obtained one that 

 measured 85 centimeters,* equal to about 34 inches. 



* Report for 1906 on the Lancashire Sea Fisheries Laboratory, p. 171. 



