CHONDRACANTHUS CORNUTUS. 169 



fringed along both sides with minnte bristles. First 

 maxillipeds with the basal part moderately stout, but 

 the end joint rather slender, and its inner edge 

 serrated. Thoracic legs short and very rudimentary. 

 Length about 6 mm. 



Male. — The cephalothorax in the male is consider- 

 ably enlarged, and apparently unsegmented ; dorsum 

 boldly rounded ; abdomen composed of three or four 

 segments. Caudal rami small. Antennules conspicuous 

 but showing little structure. Second maxillipeds 

 armed with small but effective and claw-like terminal 

 hooks. Length scarcely 0*5 mm. (- 5 -q of an inch). 



Habitat. — Parasitic, usually inside the gill-covers of 

 plaice (Pleuronectes platessa) . The species is tolerably 

 frequent, and has been recorded from various parts of 

 the British coasts. In the drawing (PL XLVII, 

 fig. 2), a male " m " is seen clinging to the female. 



Some variation has been observed in specimens belonging 

 to this species as shown by figs. 1 and 2 in PL XLVII, some 

 being longer and narrower than others and with the thoracic 

 legs less developed, but these seemed to be the only differ- 

 ences between them. 



2. Chondracanthus annulatus Olsson. 



(Plate XX, fig. 9; Plate XLVII, fig. 3; Plate LVI, 



figs. 8-10.) 



1868. Chondracanthus annulatus Olsson. (92) p. 30, pi. ii, figs. 13-15. 



1880. Chondracanthus Ixvirajse Delia Valle. (141a) Boll. Soc. Adriat. 

 Sc. Nat., vol. vi, p. 73. 



1900. Chondracanthus annulatus T. Scott. (112) p. 164, pi. vii. figs. 

 16 51. 



1909. Chondracanthus inflatus Bainbridge. (3) p. 47, pi. ix, figs. 9-15. 



1910. Chondracanthus annidatus Norman & Brady. (87a) p. 156. 



Female. — Body elongated, moderately narrow and 

 cylindrical, about four times longer than broad, and 

 only slightly flattened. Head small but well defined ; 

 the thorax also fairly well marked and the head and 

 thorax combined equal to about one-third of the entire 

 length of the animal. Genital segment, which con- 

 stitutes the other two-thirds, showing a slight constric- 



