(i 



G. O. SARS. 



[Xo. 1. 



I. 



Generic and Specific Characters. with Reruarks on 

 Affinity and Synonymy. 



Order Branchiopoda. 



Suborder Ph yllopoda . 

 Section Con cl i ost) a ca . 

 Fam. Limnadiidæ. 

 Genus Cyclestheria, G. 0. Sårs. u. 



Generic Characters. — Shell more or less orbicular, ineguilat- 

 eral, with distinctly prominent umbones and but few lines of 

 growth. Animal comparatively less massive than in Estheria. 

 admitting of being completely withdrawn into the shell. An- 

 terior part of head strongly compressed. or surrounded by a thin 

 crest rounded in front. A deep occipital incision present, as in 

 Estheria. Eyes united to a single organ, removed from the 

 anterior edge of the head. Ocellus very large, triangular, close 

 below the compound eye. Antennulæ simple cylindrical, neither 

 articulate nor lobular, extremity slightly dilated. Antennæ 

 råtner stout, brauches subecLiial, upper branch and part of scape 

 with strong recurved spines. Sixteen pairs of legs, successively 

 deereasing in length posteriorly; first pair (in female) with a 

 rounded expansion anteriorly, bearing a number of strong curved 

 setæ. Endopodite of legs with all the lobes comparatively short 

 and setiferous; exopodite with upper part more or less produced 

 and forming in female a lamellar setiferous expansion. terininatiiig 



