452 MR. G. S. BRADY S MONOGRAPH OF 



the last pair of feet longer than the two following; " terminal claw very long and slender. 



No eves. 



Length -^ in. 



J lab. In depths of 10-GO fathoms. The Hebrides and the Minch, Shetland and Channel Islands (Mr. J. 



(i. Jeffrey*) ; Aberdeenshire (Mr. Dawson) ; Macduff and Ormeshead (Mr. D. Robertson) ; Northum- 

 berland coast and Arranmore, Ireland (G. S. B.) ; Devonshire coast (Mr. C. Spence Bate) ; and in 

 shell-sand from Roundstone (Dr. Alcock). 



Though widely distributed, this is rather a rare species, and at the same time a very 

 beautiful one. I regret that the specimens in my collection have not enabled me to 

 examine accurately the internal animal structure ; and for this reason there may, perhaps, 

 be some doubt as to the sexual relations of the two forms of shell here described and 

 figured. The more elongated (Pmale) form is the commoner of the two, but in none of 

 my specimens have I found the animal : in one example of the stouter form I found the 

 animal in a rather imperfect state, and have no reason to doubt that it is the female; 

 t he greater abundance of the form supposed to belong to the other sex, however, is 



curious. 



:{. Bythoctthere turgida, G. 0. Sars. (Plate XXXIV. figs. 35-38.) 



Ihjthocyth<re turgida, G. O. Sars, loc. cit. p. 84. 



(< 



y tumid ; lateral protuberance large and obtuselv angular hehind ; ventral 



surface nearly flat ; dorsal evenly arched. Shell of the female, seen from the side, sub- 

 rhomboidal, nearly equal in height before and behind, greatest height equal to much more 

 than half the length ; anterior extremity obliquely rounded, posterior somewhat produced 

 above the middle ; superior margin a little arched, inferior slightly sinuated ; lateral pro- 

 tuberance rather prominent in the middle; seen from above very broad, subhexagonal, 

 greatest width somewhat exceeding the height, and situated behind the middle, tapering 

 gradually in front, suddenly behind ; posterior extremity forming an acuminate triangular 

 process. Shell of the male a little more elongated, higher behind than in front ; superior 

 margin straight in the middle, arched behind. Surface ornamented with a few small 

 rounded impressions, which are larger and more numerous on the ventral surface ; pos- 

 terior margin armed below with five to seven minute teeth. Colour white, with a few 

 rod spots on the dorsal aspect. Eyes separate. Penultimate joint of the upper antennse 

 equal in length to the preceding. Branchial appendage of the mandible-palp bearing 

 eight setae, gradually decreasing in length towards the front, the two anterior rudimen- 

 tary, one overlapping the other. Second joint of the last pair of feet shorter than the 

 united length of the two following joints. Apical portion of the male copulative organs 

 produced downwards, elongated, subtriangular or lanceolate." 



The single shell figured in Plate XXXIV. was unaccountably lost or mislaid before 

 my drawings were completed. I have no record of the locality ; but it was probably 

 taken off Holy Island on the Northumberland coast, and seems to me, from a comparison 



of the figures with Sars's description, quoted above, to be referable to Bythocy there 

 turgida. 



Length -^ in. 



