213 



joint armed with 3 strong claw-like spines and 2 geniculated setse; inner ramus 

 with the last joint a little larger than the middle one, both together about half 

 the length of the 1st. Natatory legs with the setse on the terminal joints of 

 the rami somewhat reduced in number. Last pair of legs not very large, distal 

 joint oval in form and provided with 6 marginal setse, inner expansion of prox- 

 imal joint extending to about the middle of the distal joint, marginal setse 5 in 

 number. 



Colour whitish. 



Length of adult female 0.64 mm. 



Remarks. This is the form originally recorded by Boeck as the type of 

 his genus Nitocra. The Carithocamptus palustris of Brady is unquestionably iden- 

 tical with Boeck's species, and I am quite unable to see any difference between 

 it and the form recorded by the same author some years later as Ameira am- 

 phibia. Dr. Giesbrecht described the species under another name, viz., Nitocra 

 oligochceta. 



Occurrence. I have met with this form in several places of the west coast 

 of Norway, as also in the Trondhjem Fjord. It is a strictly littoral species, found 

 in more or less brackish water and occasionally also in tidal pools. 



Distribution. British Isles (Brady), bay of Keel (Giesbrecht), Dutsh coast 

 (v. Breemen), coast of France (Canu), Novaja Zemlia (Scott). 



135. Nitocra spinipes, Boeck. 



(PI. CXXXIX). 

 Nitroca spinipes, Boeck, 1. c. p. 274. 



Syn: Canthocamptus palustris, var. elongata, Scott. 



Specific Characters. Female. Very like the preceding species, but of 

 larger size and still more slender form of body. Last segment of urosome, as 

 in that species, coarsely spinulose at the end, and having the anal opercle edged 

 with strong denticles. Caudal rami spinulose not only on the edge, but also 

 dorsally. Anterior antennas resembling in structure those of N. typica, but with 

 the 2 basal joints comparatively more dilated and the 3rd joint shorter than 4th. 

 1st pair of legs with the inner ramus scarcely as long as the outer, the last 2 

 joints of about equal size and combined attaining almost the length of the 1st, 

 the latter with a series of spinules outside its distal part. Natatory legs with 

 the setse of the terminal joints less reduced in number. Last pair of legs resemb- 

 ling in shape those in N. typica, distal joint however with only 5 marginal setse, 



28 Crustacea. 



