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Part III. — Eighteenth Annual Report 



cornutus as there are for separating Chondr •acanthus clacatus from the 

 same species. 



The male of Chondr acanthus solew resembles also in some respects the 

 male of Chondr 'acanthus coniutus, but appears to differ in the form of the 

 antennules and of the second pair of thoracic feet (figs. 44, 45) ; the 

 antennules are considerably dilated and of a somewhat triangular form ; 

 and the second pair of feet have a sub-quadrate outline. 



A moderately large female, obtained on a specimen of Solea vulgaris 

 captured in the Clyde, measured about 8'5mm., exclusive of the ovisacs, 

 which were as long as the specimen itself. In this specimen the lateral 

 processes at the posterior end of the thorax were a millimetre in length, 

 which was somewhat less than in some of the other specimens examined. 



Chondr acanthus ./force, Kroyer. (PI. VII., figs. 32-34.) 



1864. Chondr acanthus flurce, Kr., op. cit., r. iii., vol. ii., 

 pp. 323 and 330, PI. XIII., fig. 6. 



Kroyer obtained this species from the long rough dab, Plztessa 

 limandoides (Bl.), or Drepanopsetta platessoides, Fabr., as this fish is now 

 called. Specimens of Chondr acanthus flune have been obtained on long 

 rough dabs captured in the Firth of Clyde ; some of them were 

 taken on specimens captured at Station III. (Kilbrennan Sound) 

 in December last. This parasite has not been observed by us on 

 any other kind of fish. Chondr -acanthus fluro j , like the one last described, 

 has the posterior portion of the thoracic segment in the female distinctly 

 constricted in the middle, but it is more robust, and the thoracic limbs, 

 as well as the posterio-lateral processes, are short. Kroyer's description 

 of the species, which accords very well with the Clyde specimens, is as 

 follows : — " Forma crassa robustaqus, latitudine fere dimidiam longitu- 

 dinis partem obtinente, capite mediocri, latiore quam longiore, sub- 

 semilunato ; annulis thoracicis omnibus perbene distinctis, latioribus quam 

 longioribus, primo secundoque insequentibus multo angustioribus. 

 Antennae anterioris paris latitudine capitis paulo breviores, basi sejunctse, 

 articulo terminali conico, seta apicis instructo. Membra annuli thoracici 

 primi et secundi minuta, eadem ferme longitudine ac latitudine, vix vel 

 parvum furcata. Processus annuli thoracici quarti posteriores ipso annulo 

 breviores (tertia quartave parte), erassi subconici. Abdomen dimidiam 

 processunm longitudinem superius conicum, biarticulatum. Ovaria 

 externa gracilia, elongata ? " * 



This species is smaller, but comparatively more robust, than the one last 

 recorded. The specimen represented by the drawing measures about 

 4*7mm. in length; while the length of a somewhat larger specimen is 

 5 '5 mm., exclusive of ovisacs, and from the forehead to the end of the 

 ovisacs the length is fully 10 "5mm. 



Chondr -acanthus merluccii, Holten. 



Chondr acanthus merluccii, Holten, Mem. Soc. Hist. Nat. 



Copenhag., vol. v., PI. III., fig. 2. 

 1892. Chondracanthus merluccii, T. Scott, Tenth Ann. Rept. 



Fish. Board for Scot., Pt. Ill , p. 262. 

 1896. Chondracanthus merluccii, Basset-Smith, Journ. M. B. 



Assoc. Plymouth, p. 161. 



This is a moderately common parasite on the hake, Merluccius vulgaris. 

 I find it most frequently clinging to the roof and sides of the mouth, and 



* Naturh. Tidsskr., R. III., Bd. 2, p. 330 (1864). 



