COMPLETE H AIG : EASTERN PACIFIC PORCELLANIDAE 1 1 



Today the group is accepted as a distinct family in the Galatheidea, 

 having its closest affinities with the family Galatheidae. 



Porcellanids are distributed throughout the tropical and temperate 

 regions of all the oceans, and are typically littoral or sublittoral; in 

 number of species they are by far the most abundant in the Pacific. Chace 

 (1951) estimated the total number of species as about 225. A great deal 

 of systematic work still remains to be done on the family as a whole. 



Key to the Eastern Pacific Genera 



la. Chelipeds normally held more or less straight out in front of 

 carapace ; carapace nearly one and a half times as long as broad, 

 lateral margins with a series of about 12-15 minute, close-set 

 spinules Orthochela 



lb. Chelipeds normally bent sharply at articulation of carpus and 



manus, with manus directed inward 2 



2a. Carapace at least one and a half times as long as broad ; a large 

 orbitlilce concavity on hepatic margin, its outer angle marked 

 by a tooth Euceramus 



2b. Carapace never as much as one and a half times as long as 



broad ; no large orbitlike concavity on hepatic margin as in 2a. 3 



3a. Basal segment of antenna short, not strongly produced forward 

 to meet anterior margin of carapace; movable segments with 

 free access to orbit (rarely, basal segment in contact with outer 

 orbital angle, narrowly excluding movable segments from 

 orbit) 4 



3b. Basal segment of antenna produced for\vard and broadly in 

 contact with anterior margin of carapace; movable segments 

 far removed from orbit 9 



4a. Posterior portion of side walls of carapace consisting of one or 



more pieces separated by membranous interspaces. ... 5 



4b. Posterior portion of side walls of carapace without separated 



pieces 6 



5a. Chelipeds thick, robust, one distinctly larger than the other; 

 front not prominent, usually transversely sinuate or rounded in 

 dorsal view Pachycheles 



5b. Chelipeds somewhat flattened, subequal ; front strongly pro- 

 duced, distinctly trilobate in dorsal view. . Clastotoechus 



