210 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.24 



Text-fig. 10. Basal segment of right antennule of Pisidia magdalenensis, x 40. 



merit with a spinule or conical tubercle on anterior margin; second 

 granular or with spinules on anterior margin ; third more or less smooth ; 

 flagellum naked or with vestigial hairs visible only under magnifica- 

 tion. Outer maxillipeds lightly rugose. 



Chelipeds lightly granular or somewhat rugose, one a little larger 

 than the other. Merus with a broad, strongly projecting rounded lobe 

 on anterior margin, lobe edged with minute spinules and often with a 

 distinct small spine; devoid of hairs or nearly so in males, pubescent 

 in females. Carpus about one and a half times as long as wide, a little 

 longer in large specimens, usually devoid of hairs in males, pubescent 

 in females; anterior margin slightly sinuous, armed with one or two 

 spinules in males, about three strong spinules and a number of smaller 

 ones in females; dorsal surface with a longitudinal crest, another along 

 posterior margin, these crests sometimes spinulate. Manus with a strong 

 longitudinal crest on dorsal surface, the crest sometimes spinulate ; a nar- 

 row crest along outer margin extending to tip of pollex, minutely gran- 

 ular or spinulate; in major cheliped, dorsal surface devoid of hairs or 

 nearly so in males, pubescent and with a long fringe of plumose hairs 

 along outer margin in females; in minor cheliped, outer half of upper 

 surface in both sexes densely covered with long plumose hairs. Fingers 

 in major cheliped shorter than palm, not contorted, meeting entire length 

 or slightly gaping, gape with a short pubescence confined to their proxi- 

 mal ends. Fingers in minor cheliped as long as palm; dactylus strongly 

 curved, twisted out of plane with manus, often spinulate along outer 

 margin, surface pubescent; pollex covered with long plumose hairs; 

 fingers strongly gaping, meeting only at tips, their inner surfaces cov- 

 ered with a dense, short pubescence extending nearly to tips, and with 

 scattered long non-plumose setae. 



