of the Fishery Board for Scotland. 



165 



compressed. The head is well defined, the neck is short, and the posterior 

 part of the thorax is slightly constricted in the middle. The abdomen is 

 very short, and so are the posterio-lateral processes of the thorax. As 

 the abdomen and lateral processes are about the same length, they give to 

 the posterior end of the thorax a more or less trilobed appearance (fig. 

 46). The specimen represented by the figure is about 14mm. (-J-j of an 

 inch) in length, exclusive of ovisacs, and from the front part of the head 

 to the extremity of the ovisacs the length is about 2 inches. 



The antennules in the female are very short and considerably dilated ; 

 the mandibles differ very little from those of Chondracantlius cornutus. 

 The two pairs of thoracic limbs are both very short. 



A male specimen, which is represented by figure 47, measured about 

 3 millimetres in length ; its antennules were smaller than those of the 

 female, and were rather more setiferous. The antennae were short, but 

 they were armed with strong, though somewhat short, terminal claws. 



Chondracantlius clavatus, Basset-Smith. (PI. VII., fig. 35-37.) 



1896. CJwndracanthus clavatus, Basset-Smith, Ann. and Mag. 

 Nat. Hist. (6). vol. 18, p. 13, PI. V., fig. 6. 



In this species the thorax increases in width towards the posterior end ; 

 the posterio-lateral appendages are of moderate length, as shown by the 

 figure (fig. 35). The antennules are considerably dilated and somewhat 

 like those of CJwndr 'acanthus cornutus in their general appearance. The 

 mandibles and the other appendages are also nearly the same as in that 

 species, but the posterio-lateral thoracic processes are considerably longer, 

 being equal to about one-sixth of the entire length of the airmal. 



The average length of the specimens I have measured is 6*5mm., but 

 some are found a little smaller and some larger. The ovisacs are also not 

 very elongate ; the largest specimens I have observed scarcely reached a 

 total length (including ovisacs) of 10mm. 



Habitat. — On the gills of lemon soles, Pleuronectes microcephalus, caught 

 in the Firth of Forth, in the Firth of Clyde, and on other parts of the 

 Scottish coast. The male of this species is very like that of CJwndra- 

 canthus cornutus. 



Chondracanthus solew, Kroyer. (PI. VII., figs. 41-45.) 



1838. Chondracanthus solece, Kr., Naturh. Tidsskr., r. i., vol. L, 

 p. 139, PI. III. 



1864. Chondracanthus solew, Kr., op. cit., r. iii., PI. II., p. 330. 



The specimens of Chondracanthus which I record under this name of 

 Kroyer 's were found on black soles, Solea vulgaris, captured in the 

 Firth of Clyde in October and December 1899, and on turbot, Bothus 

 maximus, captured in the Firth of Forth in July 1892. Kroyer obtained 

 his specimens also from black soles. The species is distinguished by its 

 comparatively small and robust form, by the comparatively elongated 

 posterior thoracic appendages, and by the elongated posterio-lateral pro- 

 cesses of the thorax. Moreover, the posterior portion of the thorax is 

 distinctly constricted in the middle, as shown by the drawing (fig. 41). 

 In comparing the antennules and antennae, the mouth organs, and other 

 appendages of this form with those of Chondracanthus cornutus, it is 

 found that, though there is a certain amount of resemblance between 

 them, differences are observable, which, taken in combination with the 

 marked difference in the general appearance of the animals, present as 

 good grounds for separating Chondracanthus solew from Chondracanthus 



