COMPLETE HAIG : EASTERN PACIFIC PORCELLANIDAE 53 



side fingers light garnet brown. Ambulatory legs cream buff with two 

 light brown bands on each segment, except dactyl where there is only 

 one. Nail of dactyl orange red. Ventral side light buff except maxillipeds 

 which are light cream color on outside and brilliant blue on inner 

 side. (Petersen, of a live specimen from the Gulf of California) 



Dark olive and bottle green speckled and mottled with sage green 

 and pea green, propodi of ambulatory legs with band of whitish pea 

 green at either end, carpus with fleck of same on middle of upper 

 side, likewise dactyl just above corneous claw, inner base of movable 

 finger of chela with brilliant spot of orange chrome not visible when 

 chela is closed. (W. L. Schmitt, of live specimens from Ecuador) 



Ecology: Petrolisthes annatiis occurs in the intertidal zone in al- 

 most any situation where it can obtain shelter: under stones, in oyster 

 and mussel beds, around mangroves, in corals and sponges, and on pil- 

 ings. In West Africa, it has been taken at depths to 25 or 30 meters, 

 or about 14 to 16>^ fathoms (Chace, 1956) ; the greatest depth at- 

 tained by specimens examined for this report was 10 fathoms. The 

 dredged material was taken on bottoms of rock and of sand and shell. 



Among the material examined are ovigerous specimens taken in 

 every month of the year. 



Remarks: As shown by the extensive synonymy above, Petrolisthes 

 armatus has been described under several different names. This is due 

 partly to its wide range, which includes both tropical American coasts 

 and the west coast of Africa, and partly to its intraspecific variability. 

 The first record of the species from the Pacific coast was that of Stimp- 

 son (1859), who reported it from "Panama" (probably Panama City) ; 

 subsequent Pacific coast records are numerous. Specimens reported by 

 Streets (1871b), Smith (1871), Nobili (1901b), Rathbun (1910), 

 and Boone (1931) were examined in connection with the present study. 



In his discussion of an Atlantic porcellanid, Henderson (1888) men- 

 tioned Petrolisthes similis, a name which had not occurred elsewhere 

 in the literature. The explanation is given by Faxon (1895, p. 70, foot- 

 note) : "Dr. Stimpson, when labelling the Crustacea in the Smithsonian 

 Institution and Museum of Comparative Zoology, separated the Pan- 

 ama specimens of Petrolisthes armatus under the name of Petrolisthes 

 similis, sp. nov., and specimens so labelled were afterward sent to the 

 Jardin des Plantes, Paris. These were seen by Professor Henderson, 

 and are referred to in his report on the 'Challenger' Anomura, p. 109, 

 as P. similis Stimps. But Stimpson, in publication, referred these speci- 



