NANNOPUS. 101 
the posterior margins. Anterior antennz short, 6- 
jointed (?); outer branches of all the swimming-feet 
3-jointed; inner branches of the first and second 
pairs 2-jointed, short, non-prehensile, of the third 
and fourth pairs obsolete and reduced to a single seta. 
1. Nannopus Patustris, nov. sp. Pl. LXXVII, figs. 
18—20. 
Anterior antennze very short and stout, scarcely 
half as long as the cephalic segment. Terminal setz 
of the outer branch of the first and second feet strongly 
and distantly plumose ; inner branch not half as long 
as the outer, first joint fringed with setz at the apex, 
second having three terminal sete. In place of 
the inner branch of the third and fourth pairs is a 
small tubercle, which gives attachment to a long 
plumose seta and two or three very small cilia. 
I have seen only one or two specimens of this species, 
which were so coated with mud that it was difficult’ to 
get a distinct view of the limbs, nor did I at first 
recognise anything very noteworthy about them, else 
possibly a little extra care might have enabled me more 
fully to elucidate their structure. There seems, how- 
ever, to be no reason to doubt the complete distinctness 
of the genus, and I therefore think it best to 
describe it, even though imperfectly. Its nearest ally 
is probably Juriua, Claus, but in that genus the third 
and fourth pairs of feet have the inner branches well 
