22 Scientific Proceedings, Royal Dublin Society. 
of two North American species (P. forficifer and P. longtrostris) 
with the general characters of Phowichilidium, but with three- 
jointed chelifori, and ten-jointed false legs in both sexes. Hoek (1) 
admitted that this genus might possibly stand, in which case three 
of his “ Challenger ”’ species, described under Phowichilidium (P. 
oscitans, P. pilosum, and P. mollissimum), would have to be trans- 
ferred to it, and possibly a fourth, P. patagonicum, in which the 
basal joint of the cheliforus is indistinctly divided. But this 
latter species seems to forbid the use of the number of joints of 
the chelifori as a generic distinction in this group, and to oblige 
us to include in the genus Pallenopsis all the species hitherto 
referred to Phowichilidium’ which have ten-jointed false legs 
without claw and with simple spines, in both sexes, and which 
may be further characterised by their rather robust bodies with 
lateral processes not widely separated, the presence of rudimen- 
tary palpi in form of paired rounded prominences below the 
cephalic segment, and the presence of two auxiliary claws on the 
ambulatory legs. This view of the genus seems to be taken by 
Schimkéwitsch (7, 10). 
The presence of false legs in both sexes places this genus in the 
family Pallenidee as defined by Sars, but the simple nature of the 
spines on the false legs, and the extension of the cephalic seg- 
ment over the proboscis (characters of much greater value), show 
its affinity to Phowichilidium. Indeed, the genera Parapaillene 
(suggested in my previous Paper) and Pallenopsis form such a 
connexion between the Pallenide and Phoxichilidiide of Sars, as 
will probably lead systematists to revert to the arrangement of Hoek 
and reckon both as one family—the Pallenide. In this family 
we have (as the one extreme) Phowichilidium (which comes nearest 
to the Phoxichilidiide) connected by Anoplodactylus, Pallenopsis, 
and Parapallene, with Pallene, which leads on in the other direc- 
tion to Neopallene, Cordylochele, and Pseudopallene, the latter genus 
occupying the frontier in the direction of the Nymphonidz. Most 
of these relations have been already indicated by Schimke- 
witsch (7). 
1TIn addition to the species already mentioned, P. fluminense, Kr. and P. Hoekii, 
Miers. 
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