COMPLETE HAIG : EASTERN PACIFIC PORCELLANIDAE 227 



Telson of abdomen with five plates. 



Material examined: See Table 68. 



Measurements: Males, 2.8 to 4.0 mm; non-ovigerous females, 2.5 

 to 4.0 mm ; ovigerous females, 2.9 to 4.8 mm. The male holotype is 4.0 

 mm in length and 3.8 mm in width. 



Color: Not recorded. All the specimens examined were faded to a 

 pale buff. 



Ecology: 41 specimens were taken by the Velero IV at a single sta- 

 tion, from sponges dredged in 1-4 fathoms. The material examined is 

 otherwise represented by eight specimens from four stations; it was 

 taken under stones in one case and from coral in another. The species 

 may occur most commonly in sponges. 



Ovigerous females have been collected in February, March, and 

 April. 



Relationships: This species, like Megalobrachium peruvianum, new 

 species, is related to M. roseum (Rathbun), 1900, from the western 

 Atlantic. The carapace of M. festai is more markedly triangular and 

 tuberculate than that of the Atlantic form; the walking legs are some- 

 what stouter; and the telson of the abdomen has five plates instead 

 of seven as in M. roseum. 



Remarks: The specimens from southern Mexico and El Salvador 

 are the first to be recorded since the holotype, which was taken in 

 Ecuador. The spottiness of these records may be due to the fact that 

 sponge masses have seldom been examined for specimens. 



Range: Acapulco, Mexico, south to Bahia de Santa Elena, Ecuador. 



Megalobrachium tuberculipes (Lockington), new combination 

 Plate 16, fig. 11 ; plate 40, fig. 4 



Pachycheles tuberculipes Lockington, 1878, pp. 396, 404 (type locality, 

 La Paz, Gulf of California) . 



Poly onyx tuberculipes, Nobili, 1901b, p. 21. Rathbun, 1910, p. 601. 



Pisonella tuberculipes, Glassell, 1938a, pp. 437, 440, pi. 34, fig. 1 

 (neotype designated; neotype locality, Punta Penasco, Sonora, 

 Gulf of California). Steinbeck and Ricketts, 1941, p. 457. 



Porcellanopsis tuberculipes, Chace, 1942, p. 100. Haig, 1957b, p. 15. 



