199 



Gen. 43. Attheyella, Brady, 1880. 



Generic Characters. Genera.} form of body about as in Canthocamptus. 

 Anterior antennae comparatively short, 8-articulate, and distinctly hinged in the 

 male. Posterior antennae with the basal part not subdivided, outer ramus of 

 moderate size and generally uniarticulate, with 4 setae, 2 lateral and 2 apical. 

 Oral parts scarcely different from those in Canthocamptus. 1st pair of legs im- 

 perfectly prehensile, with the inner ramus in most cases only consisting of 2 joints 

 and scarcely longer than the outer, more rarely 3-articulate and somewhat more 

 elongated. Inner ramus of the 3 succeeding pair of legs poorly developed, bi- 

 articulate, with the 1st joint, as a rule, very small; that of 3rd pair in male 

 conspicuously transformed. Last pair of legs of somewhat varying shape in the 

 different species. 



Remarks. This genus, established by Brady, is closely allied to Cantho- 

 camptus, and its validity may perhaps be disputed, especially as the structure of 

 the 1st pair of legs, at least in 2 of the species, approaches rather nearly to that 

 found in the above-named genus. Yet in all the species of the present genus 

 the inner ramus of the 2 succeeding pairs differs conspicuously from that in Cantho- 

 camptus, being much shorter and, like that of the 4th pair, only consisting of 2 

 joints. The genus comprises several species, 5 of which belong to the fauna of 

 Norway. They are all exclusively freshwater forms. 



125. Attheyella crassa, G-. 0. Sars. 



(PI. CXXIX). 



Canthocamptus crassus, G. O. Sars, Oversigt af de indenlandske Ferskvandscopepoder. Chr. Vid. 



Selsk. Forh. L 1862, p. 23. 



Syn: Attheyella spinosa, Brady. 

 Paratachidius inermis, Brady. 



Specific Chararters. Female. Body comparatively short and thick, cylind- 

 ric of form, slightly tapered behind. Cephalic segment broadly rounded in front, 

 with the rostral projection very small. Urosome much shorter than the anterior 

 division, and having the segments fringed at the end ventrally and laterally with 

 unusually long and closely set spinules; last segment somewhat shorter than the 

 preceding ojie, anal opercle quite smooth. Caudal rami about the length of the 

 anal segment, and of rather a peculiar appearance, being instricted at the base 

 and sub-pyriform in shape, with the inner edge strongly convex and the end nar- 

 rowed to an obtuse point, apical setae more or less strongly twisted and bent 



