204 BRITISH PARASITIC COPEPODA. 



defined. Both pairs of maxillipeds large and 1111- 

 cinate. 



The male shows a closer relationship with the male of 

 Clavella than with that of Lernieopoda. 



1. Brachiella thynni Cuvier. 

 (Plate LXIV, figs. 4-6.) 



1817. Brachiella thynni Cuv. (37) p. 287, pi. xv, fig. 5. 



1829-1843. Brachiella thynni Guerin-Meneville. (55) pi. ix, fig. 6 a-c. 



1832. Brachiella thynni Nordmann. (89) p. 90. 



1840. Brachiella thynni M. Edwards. (43) p. 512. 



1851. Brachiella thynni P. J. van Beneden. (11) p. 128. 



1861. Brachiella thynni Stp. & Liitk. (127) p. 420, pi. xv, fig. 36. 



1877. Brachiella thynni G. Yogt. (142) p. 426. 



1896. Brachiella thynni Bassett-Smitb. (7) p. 162. 



1906. Brachiella thynni Norman & T. Scott. (88) p. 219. 



Female. Ceplialotliorax slender, flexuose, fully as 

 long as the genital segment, and separated from it by 

 a more or less distinct articulation or constriction. 

 Genital segment narrow at its union with the cephalo- 

 thorax but becoming gradually enlarged towards the 

 posterior end, where the width is equal to about half 

 the length ; the posterior end abruptly truncated and 

 furnished with two pairs of elongated and moderately 

 slender appendages, one pair springing in front of and 

 the other behind the base of the egg-strings, which 

 thus issue from between them, each having at its 

 base an appendage both in front and behind ; the 

 appendages on the ventral aspect scarcely so elongated 

 as the others, and about as long as the genital seg- 

 ment. That segment also somewhat flattened and 

 with several transverse constrictions more or less indis- 

 tinct, imparting to it an obscure lobate appearance. 



Antennules small, three- jointed. Antennae stout, 

 moderately large, and furnished with a few apical 

 spines. Mandibles narrow, elongated, inner margin 

 near the distal end coarsely toothed, the teeth being 

 to some extent alternately larger and smaller. Maxillas 

 small, furnished Avith two or three moderately stout 

 apical setae and one or two minute submarginal 



