81 



Remarks. This genus was established by the present author as early as the 

 year 1863, to include a peculiar fresh-water Calanoid found in the largest Norwegian 

 lake, Mjosen. The name refers to the habits of this Calanoid, which somewhat 

 recall those of the marine Calani. It is, however, in reality very different, as 

 proved by the structure of the several appendages, and it does not even belong to 

 the same section. In the slender form of the body and the narrow elongated 

 caudal rami, the species of this genus resemble some of the Temoridos, especially 

 the genus Temorella of Glaus ; but the structure of the last pair of legs is very 

 different, and exhibits a much closer resemblance to that in the genus Cenlropages. 

 Indeed, one of the species was on this account referred to that genus by M. de 

 Guerne. There are, however, sufficient reasons for keeping the present genus 

 apart, though it must undoubtedly have a place in the family Centropagidce, 

 as here defined. We know at present of 3 different species belonging to this 

 genus, viz., L. macrurus, G. 0. Sars, L. Grimaldii, de Guerne. and L. sinensis, 

 Poppe. The first and last species have hitherto only been found in fresh-water 

 lakes, whereas the 2nd is a more strictly marine form, though also occurring in 

 the Caspian Sea. Only the first-named specie:; belongs to the fauna of Norway. 



33. Limnocalanus macrurus, G. 0. Sars. 



(PL LV, LVI). 



Limiwcalanus mctcrum*, G. O. Hars. Oversigt af de indenlandske Ferskvandscopepoder. 



Chr. Vid. Selsk. Forh. 1862, p. 17. 



Specific Characters. Female. Anterior division of body, seen dorsally, 

 narrowly elliptical in outline, greatest width but slightly exceeding l / 3 of the length, 

 anterior extremity narrowly rounded, posterior somewhat contracted; seen laterally 

 only very slightly vaulted above. Cephalosome with a very conspicuous cervical 

 sinus, in front of which the dorsal margin is gibbously convex and declines 

 obliquely to the short rostral protuberance. Urosome (including the caudal rami) 

 exceeding the metasome in length, genital segment somewhat larger and thicker 

 than the middle one, last segment the smallest. Caudal rami narrow linear and 

 scarcely at all divergent, equalling in length the last 2 caudal segments combined, 

 their dorsal face clothed with numerous small spikes ; outermost seta shorter than 

 the others, and issuing from the outer edge at some distance from the apical ones. 

 Anterior antennae, when reflexed, reaching about to the end of the middle caudal 

 segment. Last pair of legs with the unguiform projection of outer ramus shorter 

 than the terminal joint, and distinctly denticulate. 



12 Crustacea. 



