PARATANAIS. 137 



ISOPODA. TANAID&. 



ABEKRANT1A. 



Genus PARATANAIS. (Dana.) 



( ' Like Tanais in having the anterior feet stout and short, and the antennas 

 without a flagellum. Caudal stylets two-branched, branches unequal, one or 

 many jointed." 



DANA, U.S. Explor. Exp. p. 798. 



THE above is Dana's short description of this genus, 

 which, being founded on a specimen taken in the Sooloo 

 Archipelago, we have only an opportunity of knowing 

 through the author's description. 



There are some important points in which our British 

 specimens differ from the above description, but they 

 appear to be rather omissions than structural differences. 



We therefore give our own character of the genus 

 founded on British specimens. 



The cephalon is fused with the first segment of the 

 pereion. The eyes are pedunculated. The antennae have 

 rudimentary flagella ; the inferior pair is more slender 

 than the superior. The first pair of gnathopoda are 

 robust and chelate ; the second feeble and moiiodactyle. 

 The pereiopoda subequal in height and resembling each 

 other in form. Pleon having six distinct segments 

 supporting six pair of pleopoda, five being double 

 ovate plates with ciliated margins adapted for swimming, 

 the sixth forming a pair of biramose substyliform ter- 

 minal uropoda. 



