COMPLETE HAIG : EASTERN PACIFIC PORCELLANIDAE 203 



fers in having only one spinule at the epibranchial angle, this spinule 

 disappearing entirely in larger specimens; in addition, in larger speci- 

 mens the spinules on either side of the median frontal tooth take the 

 form of small lobes projecting from the sides of the median tooth. 

 Otherwise no significant differences were noted. More detailed studies 

 of both species may be necessary to determine whether the east and 

 west American populations should both be accorded full specific rank. 



Remarks: Porcellana cancrisocialis was previously reported only 

 from the Gulf of California and from Ecuador. Specimens are now 

 known from many stations in the intervening territory. 



Range: Bahia de Santa Maria and Punta Tosco, Baja California; 

 Punta Penasco, Gulf of California, south to Bahia de Santa Elena. 

 Ecuador; Isla Isabel off the Mexican coast. Shore to 54 fathoms. 



Porcellana paguriconviva Glassell 

 Plate 38, fig. 1; text-fig. 9(3) 



Porcellana paguriconviva Glassell, 1936, p. 293 (type locality, Punta 

 Penasco, Sonora, Gulf of California) ; 1937, p. 87. Steinbeck and 

 Ricketts, 1941, p. 458. 



Previous records: Gulf of California. Punta Penasco, Sonora; 

 S. A. Glassell (Glassell 1936). Bahia de Santa Ine's: Zaca (Glassell 

 1937). Bahia Concepcion: J. Steinbeck and E. F. Ricketts (Steinbeck 

 and Ricketts). 



Diagnosis: Carapace nearly flat transversely; median frontal tooth 

 broad, projecting far beyond narrow lateral teeth, all three rounded at 

 tips; epibranchial angle rounded, unarmed; carpus only slightly longer 

 than wide, anterior margin with a strongly projecting, rounded lobe, 

 margins converging from its highest point; fingers opening horizon- 

 tally or somewhat obliquely; telson seven-plated. 



Description: Carapace covered with faint transverse plications and 

 punctae; nearly flat transversely; regions not distinct; naked or with 

 a faint pubescence on anterior regions. Median frontal tooth broad, 

 rounded at tip, with a faint median groove, projecting far beyond 

 lateral teeth, the latter narrow, rounded at tips, directed forward, and 

 extending beyond eyes. Outer orbital angle produced into a broad 

 rounded tooth. Epibranchial angle rounded, distinct, unarmed. 



Movable segments of antenna more or less smooth, without projec- 

 tions; flagellum naked or with vestigial hairs visible only under magni- 

 fication. Outer maxillipeds lightly rugose. 



