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127. Attheyella pygmaea, G. 0. Sars. 



(PI. CXXXI). 

 Canthocamptus pygmwus, G. 0. Sars, 1. c. p. 21. 



Syn : Attheyella cryptorum, Brady. 

 Canthocamptus Borcherdingi, Poppe. 





Specific Characters. Female. Body not much elongated, cylindric of form, 

 being only slightly attenuated behind. Rostral projection almost obsolete. Uro- 

 some much shorter than the anterior division, its segments distinctly spinulose at 

 the hind edge ventrally and laterally; last segment shorter than the preceding 

 one, and having the anal opercle rather prominent and edged with about 10 coarse 

 spinules. Caudal rami comparatively short and thick, being scarcely longer than 

 they are broad, and armed, in addition to the setae, with several small denticles 

 both inside and outside, outer edge angularly curved in the middle, inner straight, 

 tip transversely truncated; apical setae rather elongated and distinctly spinulose, 

 distal seta of the outer edge attached close to the apex. Anterior antennae short, 

 with the proximal joints rather dilated, terminal part fully as long as the prox- 

 imal one. Posterior antennae with the outer ramus of moderate size and distinctly 

 biarticulate. 1st pair of legs rather short, with the rami subequal in length, the 

 inner one composed of 2 joints only, both of about same length. Natatory legs 

 rather strongly built and of a similar structure to that in A. crassa. Last pair 

 of legs with the distal joint small, of rounded form, with 5 marginal setae, the 

 innermost of which is quite short, inner expansion of proximal joint rather large, 

 broadly linguiform and extending beyond the distal joint, maginal setae rather 

 unequal and 6 in number. 



Male exhibiting the usual sexual differences. 2nd pair of legs somewhat 

 unlike those in female, the outer ramus being comparatively shorter and stouter, 

 with the spines of the outer edge much coarser, inner ramus extending nearly as 

 far as the outer and narrowly exserted at the tip, which carries a single slender 

 seta. Inner ramus of 3rd pair of legs transformed in a similar manner to that 

 in the 2 preceding species, though having only a single apical seta; that of 4th 

 pair exceedingly small and apparently uniarticulate, with 2 unequal seta? on the 

 tip. Last pair of legs, as usual, much smaller than in female, with the inner 

 expansion of proximal joint less produced and only provided with 2 unequal 

 spiniform setae. 



Colour whitish, sometimes with a slight reddish tinge. 



Length of adult female 0.52 mm. 



Remarks* This is the smallest of the Norwegian species of the present 

 genus, and is moreover easily recognised by the coarsely spinous anal opercle 



