426 MESSES. T. A>'D A. SCOTT— EEVISION OF THE BRITISH COPEPODA 



we caunot say. The formula shows approximately the proportional lengths of the 

 ioints : — 



No. of the joints : 1 . 2 . 3 ■ 4 . .5 . 6 _ 



Proportional lengths : 14 9 12 5 7 9 



The secondary branches of the antennae are very slender and 3-jointed, and shorter 

 than the primary branches ; first two joints, hut especially the second, very short (PL 35, 

 fig. 13). 



Mandibles well developed, the biting part broadly truxicate and armed with several 

 blunt-iiointed teeth ; the branches of the palp are fiu-nished with plain seta? (PL 35. 

 fig. 2i). 



Anterior foot-javrs stout, the first joint furnished with two marginal seliferous 

 processes in addition to several setae (PL 35. fig. 31). 



Posterior foot-jaws small ; the first joint bears on its distal end two long and stout 

 setae, which are plumose only on one side, and tlie second has its inner margin fringed 

 with cilia (PL 35. fig. 31). 



The first four pairs of swimming-feet are somewliat similar in structure to those of 

 BradyafHsca. 



The fifth pair somewhat resemble those of Bradya fusca, but the inner portion of the 

 basal joint is not so much produced and does not reach the middle of the secondary 

 joint; the two terminal spines of the produced inner part of the basal joint are very 

 unequal in length, and there are a few small teeth round the inner margin and end of 

 this part of the joint ; the exterior angle of the same joint is also produced into a long 

 conical lobe that extends well down the side of the secondary joint, and terminates in a 

 slender hair ; the secondary joint is broadly oblong, and ends in a trilobed extremity 

 which reaches considerably beyond the basal joint ; the middle lobe is larger and more 

 produced than the lateral ones, which are subequal ; each lol^e forms the base of an 

 elongate and spiniform plumose seta ; the middle seta is rather longer and stouter than 

 the other two ; a slender seta springs from near the base of the same joint, and there are 

 transverse rows of niinvite seta? on the lateral aspect of the basal joint, as shown m the 

 figure (PL 36. fig. 5). 



Caudal stylets short, about equal in length to the last al)dominal segment (PL 36. 

 fig. 9). Colour brownish. 



Habitat. Pirth of Forth, off St. Monans; rock-pools on the shore of Hilbre Island, 

 Liverpool Bay. 



Bemurks. The eye-like dusky pigment-si^ot at the base of the antennides, together 

 with the structure of the autennai and mouth-organs, are characters which readily 

 distinguish this from other British species of Bradya. 



Genus Ectinosoma, Boeck (1864). 

 Descrijjtioit. Body elongate, fusiform, similar to that of Bradya. 



Antennules 5- to 7-jointed, not longer than the first thoracic segment, and usually 

 tapering more or less towards the distal end. 



