656 A SYNOPSIS OF THE BRITISH PAUROPODA 



Genus PAUROPUS, Lubbock. 



The lower antennal branch with the fore margin shorter 

 than the hind, and its anterior flagellum shorter than the 

 other; the stalk of the globulus as a rule considerably shorter 

 than its diameter, never longer. Sternum of the anal segment 

 with at least two, though more occasionally with three pairs 

 of setae. 



Hansen refers most of the twenty-one species dealt with to 

 three groups, of which F. huxleyi, P. dank us, and P. vidgafis 

 may be regarded as the respective types. As we recognize these 

 three forms (and another) as British, we can conveniently 

 adopt a modified form of Hansen's tabulation, as follows : — 



1. Size larger, i'3 to i"5 mm., and more robust. The anal plate with 



four long branches in the same plane, of which the inner pair is 

 longer than the outer. Anterior ventral setas on the anal segment 

 at least moderately long. Last pair of legs comparatively longer. 

 (Anterior flagellum of the lower antennal branch only slightly shorter 

 than the posterior). P. huxleyi, Lubb. 



2. Size smaller, o"6 to 0*9 mm., more slender. Anal plate with two, 



four (or six) branches, if with four the inner pair is either rudi- 

 mentary or placed on a decidedly higher plane than the outer. 

 Anterior ventral setas on the anal segment short or obsolete. Last 

 pair of legs comparatively shorter. (Anterior flagellum of the lower 

 antennal branch one-half, or less than one-half the length of the 

 posterior). 



i. Anal plate with four well -developed branches in two planes. 

 (Last pair of tactile setae proximally naked and distally 

 faintly pubescent). Form slender. P. vulgaris, Hansen. 



ii. Anal plate with two well-developed branches ; inner branches 

 absent or obsolete. (Last pair of tactile seta; normal). 



a. Species larger, 075 to 0.85 mm. Anal plate posteriorly 

 rather broadly rounded, with its two branches pro- 

 jecting from its hind margin as short cylindrical 

 processes not far from each other ; styli shorter and 

 broadly claviform ; upper antennal branch distinctly 

 longer than the lower. Form somewhat robust. 



P. dauicus, Hansen. 



