25 



differences from that genus refer to the structure of the anterior antennae and the 

 caudal rami, partly also to that of the natatory legs. We do not know at present 

 of more than a single species, to be described below. 



12. Eucanuella spinifera, Scott. 



(PL XIV). 



Eucanuella spinifera, Th. Scott in 19th Report of the Fishery Board for Scotland, Part III,- 

 Scientific Investigations, p. 245, PL XVIII, figs. 110. 



Specific Characters. Female. Body moderately slender and conspicuously 

 attenuated behind. Cephalic segment comparatively large, exceeding in length the 

 4 succeeding segments combined, and evenly vaulted above, lateral parts rather 

 deep, partly including between them the oral appendages, rostrum projecting 

 considerably. Epimeral plates of the 3 succeeding segments projecting behind in a 

 somewhat spiniform corner. Last segment of metasome slightly produced on each 

 side, but without any distinct dentiform projection. Urosome (including the caudal 

 rami) shorter than the anterior division, genital segment rather broad, with the 

 lateral projections very prominent. Last caudal segment longer than the pre- 

 ceding one, and gradually tapering distally; anal opercle somewhat prominent, 

 semilunar. Caudal rami conspicuously asymmetrical, the right one projecting con- 

 siderably beyond the left, and nearly as long as the last 2 segments combined^ 

 both gradually tapering distally, and exhibiting outside, at some distance from 

 the base, a small spinule; dorsal face with 3 delicate bristles, 2 of which occur 

 near the tip, the 3rd in front of the middle; tip with only 2 setae, the inner of 

 which is more than twice as long as the outer. Anterior antennae with the 4 

 proximal joints considerably expanded, 2nd joint armed with a strong spiniform 

 projection issuing from the upper face and pointing backwards. Outer ramus of 

 1st pair of legs scarcely inferior in size to that of the succeeding pairs, and 

 fully twice as long as the inner. Last pair of legs with the outer digitiform 

 process of the proximal joint rather thick, distal joint narrow linear, with one 

 apical and 2 lateral setae. Ovisac comparatively small, rounded. 



Colour whitish gray. 



Length of adult female 1.30 mm. 



Remarks. The above-described form is unquestionably identical with that 

 recorded by Th. Scott under the above name. It may at once be recognized 

 from any of the other Cerviniidce by the characteristic structure of the caudal 

 rami, as also by the conically-produced rostral plate. 



4 Crustacea. 



