BELONGING TO THE GENEEA BEADYA AISJ) ECTINOSOMA. 435 



(PI. 36. fig. 43). The ujoproximate proportional leng-tlis of tlic joints arc shown by the 

 formula : — 



No. of the joints : 1 . 2 . 3 . 4 . 5 . (? (i) 



Proportional lengths : 15 y II b 3 (73) 



Antennules stout, -well developed, armed with strong plumose sette ; secondary branches 

 3-jointed, shorter than the primary branches ; the middle joint is equal to about half 

 the length of the first and a third of the length of the last joint (PL 37. fig. 4). 

 Mandibles stout, furnished at the apex with tw^o strong teeth, — one bifid, the other 

 conical, — and a few small spines ; mandibular palp somewhat like that of Ectinosoma 

 elongatum, but more strongly setiferous (PL 37. fig. 17). 



Anterior foot-jaws dilated, apparently 5-jointed ; the first joint is considerably larger 

 than all the others together, the terminal joints very small; two of the marginal 

 processes are each armed with a stout spine and a few seta?; the subapical claws are 

 strong and slightly curved, the terminal setoe few and comparatively short (PL 37. 

 fig. 31). In the structure of the anterior foot-jaw's this species connects Ectinosoma 

 with Bradya. 



Posterior foot-jaws cylindrical and slightly distorted, much smaller than those of 

 Ectinosoma Sarsl ; the end-joint, which is equal to about one-third the length of the 

 middle joint, bears one stout and strongly plumose, and one long, slender, and plain 

 terminal seta ; a short seta also springs from near the proximal end of the upper margin 

 (PL 37. fig. 53). The outer branches of the first pair of swimming-feet are short, being 

 only about three-fifths of the length of the inner branches ; a long plumose seta sj^rings 

 from the oviter angle of the second basal joint, and a moderately stout spine from the 

 interior angle; the fourth pair are somewhat like the first, but the outer branches are 

 proportionally rather longer, and the seta on tlic outer angle of the second basal joint is 

 plain, and there is no spine on the inner angle (PL 38. figs. 14 and 19). 



The fifth pair is small ; the secondary joint is subqnadrate and scarcely reaches beyond 

 the produced inner portion of the basal joint ; the middle apical seta of the secondary 

 joint, and the inner one on the truncate apex of the produced inner portion of the basal 

 joint, are stout, slightly curved, and of great length (PL 38. fig. 37). 



Caudal stylets very short and somewhat wide apart ; abdomen clothed wdth transverse 

 rows of minute hairs (PL 38. fig. 43). 



Habitat. Firth of Porth, west of May Island, 



Hemarks. The species now described is readily distinguished from any of the others 

 recorded in this Report, by its robust form, by the structure and armature of the 

 antennules and antenna;, and especially by the form and by the peculiarly elongate 

 setffi of the fifth pair of thoracic feet. 



Ectinosoma Normani*, sp. n. (PL 36. figs. 21, 29, 39; PL 37. figs. 12, 26, 34, 51 ; 

 PL 38. figs. 5, 18, 42, 45.) 



Description. Length "55 mm. (^5- of an inch). The thorax seen from the side 

 is broadest at the posterior end of the first body-segment, and from thence the 



* In compliment to the Rev. A. M. Norman, F.E.S., &c. 

 SECOND SERIES. — ZOOLOGY, VOL. VI. 58 



