184 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 24 



Merus of walking legs devoid of hairs, greatly expanded and flat- 

 tened, with a sharp crest on anterior margin; carpus devoid of hairs, 

 rounded on anterior margin, a faint crest sometimes present on dorsal 

 surface; propodus with short tufts of hairs distally, and a single pair 

 of small posterior movable spinules at articulation with dactylus; dac- 

 tylus with short tufts of hairs, posterior margin without movable spin- 

 ules but with small corneous vestiges where they would normally occur. 



Material examined: Estacion de Biologia Marina, Montemar, Chile, 

 shore; September 19, 1948; Lund University Chile Expedition station 

 M123; one male (Allan Hancock Foundation, gift of H. Brattstrom). 



Valparaiso, Chile; Guerin collection [Favorite, collector?]; one 

 dry specimen, not sexed, [syn?]type (Academy of Natural Sciences of 

 Philadelphia Cat. No. 4133). 



Talcahuano, Chile; 1872; Hassler Expedition, collector; twelve fe- 

 males (four ovigerous) (Museum of Comparative Zoology Cat. No. 

 7952). 



Measurements: Males, 8.9 to 34.0 mm; non-ovigerous female, 9.0 

 mm; ovigerous females, 27.8 to 35.0 mm. The 34.0 mm male and 35.0 

 mm female were collected by the Lund University Chile Expedition. 

 The type of Porcellana cristata H. Milne Edwards, of unspecified sex, 

 was 9 lines (about 20.3 mm) in length. Cano (1889) reported a 38 mm 

 male. 



Color: Specimens preserved in alcohol were brick-red; markings, 

 which were the same shade of red but darker, consisted of reticulations 

 on the chelipeds, spots and less strongly marked reticulations on the 

 carapace, and many very small spots on the walking legs and abdomen. 



Ecology: The species has been taken under stones in the Intertidal 

 zone. The Lund University Chile Expedition recovered it on one occa- 

 sion from the hull of a barge. 



The Lund University Chile Expedition collected an ovigerous fe- 

 male at Montemar in October ; ovigerous females from the Hassler Ex- 

 pedition were taken at Talcahuano, probably in April. 



Remarks: This appears to be the largest of the porcellanid species 

 with the exception of Petrolisthes desmarestii (Guerin), which also in- 

 habits the Peruvian faunal province. In spite of its large size and strik- 

 ing appearance Allopetrolisthes punctatus is apparently rare, for it has 

 been taken on relatively few occasions and never in abundance. The 

 extensive shore collecting and dredging in Peru by the Velero III 

 and Hancock Expedition collectors failed to recover it. 



