214 



and inner expansion of proximal joint extending beyond the middle of the distal 

 joint; those in male, as usual, of smaller size, with the inner expansion of prox- 

 imal joint less prominent and only provided with 3 short seta?. 



Body of whitish colour, with a more or less distinct yellowish tinge. 



Length of adult female 0.76 mm. 



Remarks. This species is closely allied to the preceding one, and may 

 easily be confounded with it. On a closer comparison, it is however found to be 

 well distinguished, not alone by its larger size and more slender form of body, 

 but also by some well-marked structural differences mentioned in the above dia- 

 gnosis. The form recorded by Th. Scott as Canthocamptus lacustris, var. dongata, 

 is unquestionably identical with the present species. 



Occurrence. I have found this form rather abundantly in the upper part 

 of the Christiania Fjord close to the beach of shallow bays near the town. Boeck 

 records it also from the west coast of Norway (Karmoen). 



Distribution. Scottish coast (Scott). 



Gen. 47. Amelra, Boeck, 1865. 



Generic Characters. Body, as a rule, rather slender and somewhat com- 

 pressed in its anterior part. Rostral projection very small, almost obsolete. Seg- 

 ments of urosome less coarsely spinulose than in the genus Nitocra; anal opercle 

 perfectly smooth. Caudal rami more generally short and scarcely spinulose. An- 

 terior antenna 8-articulate, with the last 2 joints very small and less perfectly 

 defined. Posterior antennae with the basal part distinctly subdivided, outer ramus 

 narrow, uniarticulate. Mandibular palp more fully developed than in the preced- 

 ing genera, biarticulate, with the basal joint more or less dilated, forming inside 

 a well defined setiferous expansion. Maxillae with the exopodal and epipodal lobules 

 not defined, accessory lobe present. Anterior maxillipeds with only a single 

 setiferous lobe inside the terminal claw-bearing part. 1st pair of legs distinctly 

 prehensile, but more slender than in the genus Nitocra, inner ramus always much 

 longer than the outer and distinctly 3-articulate. Natatory legs with both rami 

 well developed, 3-articulate, the inner one not transformed in the male. Last pair 

 'of legs comparatively small, distal joint more or less contracted distally, inner 

 expansion of proximal joint not much produced. 



Remarks. -This is also one of the genera established by Boeck, the exact 

 definition of which has proved to be rather difficult, on account of the imperfect 



