PARATANAITS. 137 
ISOPODA. TANAID&. 
ABERRANTIA., 
Genus—PARATANAIS. (Dana.) 
‘¢ Like Tanais in having the anterior feet stout and short, and the antenne 
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 antenne 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 monodactyle. 
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. 
