_84 



containing saline water; but no true marine forms have as yet been met with. 

 We know at present of at least 2 distinct genera belonging to this family, viz., 

 Diaptomus, Westwoocl, and Paradiaptomus, G. 0. Sars 1 ). Only the former genus 

 is represented in the fauna of Norway. 



[Gen. 23. Diaptomus, Westwoocl, 1836. 



Syn: Glaucea, Koch. 



Qyclovsma, M.-Edw. (part). 



Generic Characters. Body more or less slender, with the anterior division 

 evenly vaulted above. Cephalosome with a well-marked cervical depression at 

 about the middle of the dorsal face, front tipped below with 2 soft appendages 

 of comparatively small size. Last segment of metasome in female generally imper- 

 fectly separated from the preceding one, lateral parts more or less expanded, and, 

 as a rule, biangular, with a small denticle at each corner. Urosome in female 

 generally 3-articulate, genital segment much the largest, and more or less dilated 

 in front, middle segment small and often imperfectly separated from the anal 

 segment. Caudal rami not very large, with the seta3 scarcely transformed in male. 

 Anterior antennae generally slender, their length in some cases exceeding that of 

 the body. Posterior antennae with the outer ramus considerably longer than the 

 inner. Posterior maxillipeds of moderate size, terminal part 5-articulate with 

 none of the setae unguiform. Terminal joint of outer ramus in the 1st pair of 

 legs with only a single spine outside. Last pair of legs in female with the 

 terminal joint of the outer ramus generally distinct and carrying 2 apical spines, 

 those in male of somewhat varying structure in the several species. 



Remarks. This genus was established by Westwood as early as in the 

 year 1836. The name Glaucea of Koch seems to date from about the same year, 

 but Westwood's name is that now generally accepted by carcinologists. The chief 

 distinguishing characters from the nearly-allied genus Paradiaptomus consist in 

 the presence of distinct, though small tentacular appendages to the front, the 

 somewhat different structure of the urosome. the fuller development of the 



*) As shown l)y the present author, this genus is identical with the genus Brotcas of 

 Loven; but as the latter name had been appropriated in Zoology at an earlier date, that 

 of Paradiaptomus ought to be restored, and according to the rules of priority, the name 

 Lovenula recently proposed by Dr. Schmeil must cede to that given to the genus by the 

 present author. 



