94 



Remarks. In the structure of the anterior antennae this form somewhat 

 resembles /. longicornis. It is, however, of much inferior size, and moreover dif- 

 fers conspicuously from that species in the peculiarly slender form of the 1st pair 



of legs, in which respect it agrees more closely with the succeeding species, /. 



< 

 gracilis, Scott. 



Occurrence.- Only a solitary female specimen of this beautiful species has 

 as yet come under my notice. It was taken, many years ago, at Christiansund 

 in a depth of 50 60 fathoms. The figure of the animal here given is a copy 

 of the coloured drawing made from the specimen when still alive. 



58. Idya gracilis, Scott. 



(PI. LV, fig. 1). 



Idyci gracilis, Th. Scott, Additions to the Fauna of the Firth of Forth; 13th Annual Eeport of 

 the Fishery Board for Scotland, p. 171, PI. IV, figs. 1321. 



Specific Characters. Female. Body comparatively slender, attenuated be- 

 hind. Cephalic segment rather broad, and somewhat exceeding in length that of 

 the 3 succeeding segments combined. Epimeral plates broadly rounded, subconti- 

 guous. Urosome considerably exceeding half the length of the anterior division, 

 and gradually tapering distally. Caudal rami unusually produced, being nearly 

 twice as long as they are broad, outermost and innermost of the apical setse 

 comparatively short, seta of the outer edge somewhat remote from the apex. 

 Anterior antennae of moderate length, 2nd joint the largest, 3rd and 4th of about 

 equal length. First pair of legs with both rami very slender, somewhat re- 

 sembling in structure those in I. elegantula, inner ramus, as usual, the longer, 

 with the 2nd joint nearly twice as long as the 1st and much attenuated distally; 

 apical claws of this ramus comparatively short. Terminal spines of outer ramus, 

 on the other hand, exceedingly slender, each with only a few cilia at the tip. 

 Last pair of legs with the proximal joint comparatively small, distal joint, how- 

 ever, rather elongated, oblong fusiform in shape, with one of the marginal seta3 

 considerably remote from the others, issuing nearly from the middle of the 

 outer edge. 



Male not much smaller than female, and exhibiting the usual sexual dif- 

 ferences. In the 2nd pair of legs, moreover, the seta of the 1st joint of the 

 inner ramus is peculiarly modified, being transformed into a strong spine minutely 

 bidentate at the tip. 



Colour not yet determined. 



Length of adult female about 1 mm. 



