388 ALLAX HAXCOCK PACIFIC EXPEDITIONS VOL. 24 



PLATE 20 



Fig. 1. Pctroiistlics niarginatus Stimpscn, femalt-. I^la Socorro, Islas 



Revillagigedo, Mexico. 

 P'ig. 2. PctroHsllies tjlasselli Haig, female paratype. Bahia Octavia, 



Colombia. 

 F'ig. 3. Prtrolistlifs scmfrlipcnsis Glassell, male. Isla Tibiiron, Gulf 



of California. 

 Fig. 4. Prtrulisthes ayassizii Faxon, male. \'enado, Panama. 



