590 
THE VOYAGE OF H.M.S. CHALLENGER. 
“ At the Admiralty Islands species were trawled in 150 fathoms (Station 219), among 
which are some of the most interesting new forms collected by the Expedition ; these are 
Platymaia wyville-thomsoni (see fig. 197), a large and fine new genus and species allied to 
Cyrtomaia and to Euprognatha, Stimpson, but characterised by the depressed suborbicu- 
late carapace, and the remarkably elongated aud dissimilar ambulatory legs, the first pair 
of which have the fourth to last joints armed with strong spines ; the second to last pairs 
are almost devoid of spines, but have the penultimate joints dilated and compressed as 
in Eurypodius ; here also was taken a new species ( Ergasticus naresi) of the genus 
Pig. 197 . — Platymaia wyville-thomsoni, n. gen. et sp. 
Ergasticus, A. M.-E., 1 distinguished from the type of the genus Ergasticus clouei, 
A. M.-E., found in the deep waters of the Mediterranean, by the different disposition of 
the spines and spinules of the carapace, and by having spines on the inferior as well as 
the superior wall of the orbit ; lastly, a remarkable new genus and species of Oxystoma- 
tous Braehyura which I propose to designate Paracyclois milne-edwardsi (see fig. 
198), allied to Calappa, Cryptosoma, and Platymera, but distinguished from the 
first mentioned genus by the rudimentary lateral wings of the carapace, which in 
Calappa are developed so as to cover the bases of the ambulatory legs, and from 
the two last by the absence of the lateral marginal spines of the carapace and by 
other characters. 
1 Rapport sur la faune sous marine dans les grandes profondeurs de la Mediterranee et de l’Ocean Atlantique, p. 17 
(1882). 
