( 14 ) 



this singular little family is hardly to be explained by any theory of transport 

 of pelagic larvae by ocean currents. 



Key to the genera of the family Pylochelidse. 



— I'tidian genera are printed in capitals. 



I. External maxillipeds cheliform : hands of chelipeds forming an operculum by their 

 apposition : — 



1. Eyes large, eyestalks very freely movable ... ... Pylochelbs. 



2. Eyes small, pale, obsolescent : eyestalks with somewhat limited 



motion _ „. ... ... ... Chiroplat^a. 



II. External maxillipeds not cheliform : — 



1. Eyes well developed : branchiae 14 pairs * : — 



i Hands of chelipeds forming an operculum ... _ Pomatochblbs, 



ii. Chelipeds not operculiform ... ... _ Mixtopagurus. 



2. Eyes very small and pale : plumose branchice 12 pairs only „. Parapvlocheles. 



By the favour of the Director of the British Museum and of Mr. Jefllrey 

 Bell, I have examined the pieces of Miers' type of Pomatocheles jeffreysi, 

 the ghost-like shell of Spence Bate's Chiroplataa cenobiia, and Henderson's 

 Pylocheles spinosus. Chiroplatcea cenobita alone of them has cheliform external 

 maxillipeds. 



I have here kept Pylocheles and Chiroplato'a distinct, but they might 

 just as well be united, as is suggested by MM. Milne Edwards and Bouvier ; 

 so also with Pomatocheles and Mixtopagurus. About Parapylocheles, however, 

 there is no confusion. 



Pylocheles, A. Milne Edwards, 



Pylocheles, A. Milne Edwards, Bull. Mus. Comp. Zool. Harvard, VHl, 1880, p. 38 

 Milne Edwards and Bouvier, Mem. Mus. Comp. Zool. Harvard, XIV, No. 3, 1893, p.l7 

 Stebbing, Hist. Crust., 1893, p. 169 : Ortmann, in Bronn's Thier Reich, Malacostraca, p. 1144 

 Young, Stalk-eyed Crust. W. Indies, etc., p. 388; Alcock, Investigator Macrura and Anomala, 

 p. 210. 



Body perfectly straight and bilaterally symmetrical, as in any Macrurous 

 crustacean : the abdominal terga all in contact. 



Carapace about half as long as the abdomen, well calcified dorsally but 

 membranous laterally, the cervical groove well defined. No rostrum. 



Abdominal terga and telson well calcified, as are the fairly well developed 

 pleura of the 2-5 somites. Telson broad, divided into two parts by a trans- 

 verse suture. Caudal swimmerets quite symmetrical, not so large or long as 

 the telson, well calcified, the outer part of the dorsal surface of both exopodite 

 and endopodite with a pavement of small sharp setose tubercles. 



* in Mixtopagurus. 



