COMPLETE HAIG : EASTERN PACIFIC PORCELLANIDAE 229 



Material examined: See Table 69. 



Measurements: Males, 1,6 to 4.6 mm; non-ovigerous females, 1.9 to 

 3.6 mm; ovigerous females, 2.1 to 3.0 mm. Lockington reported speci- 

 mens of about 3.5 by 3.5 mm. Glassell's male neotype measures 4.1 mm 

 in length, 3.9 mm in breadth. 



Color: In life, muddy gray with a dark patch on the central re- 

 gions; in alcohol, light pink. (Glassell, 1938a) 



Ecology: "This little crab is found on sponge incrusted sea-fans, 

 but more frequently on the rough sponges themselves, at extreme low 

 water. They are quite numerous, though obscure." (Glassell) Steinbeck 

 and Ricketts reported it from a sponge mass, and most of the Hancock 

 Foundation specimens were taken under similar circumstances. It was 

 once dredged by the Velero III in 5-10 fathoms from a rock, coral, 

 and nullipore bottom. It has also been taken in coral from shore to 

 a depth of about two fathoms, and under stones in the intertidal zone. 



Ovigerous females have been taken in February and in May. 



Relationships : This species is very closely related to Megalobrachiuni 

 soriatum (Say), 1818, which ranges from Cape Hatteras to the Florida 

 Keys and is known from a few Caribbean localities. In the small amount 

 of material seen by the writer, M. soriatum appears to have a less hairy 

 carapace and walking legs than does the Pacific species. It is not known 

 whether these differences are constant ; the Pacific and Atlantic popu- 

 lations are perhaps not specifically distinct. 



Range: Punta Penasco and San Felipe, Gulf of California, south to 

 Bahia de Santa Elena, Ecuador. Shore to 10 fathoms. 



ULLOAIA Glassell 1938 



IJlloaia Glassell, 1938a, p. 434 (type species Ulloaia perpusillia Glas- 

 sell, 1938, by original designation). 



Carapace longer than broad, surface covered with large protuber- 

 ances, lateral margins dentate. Front broad, sharply deflexed, with a 

 rostral process, visible only in frontal view, consisting of a broad, 

 rectangular lobe. Orbits deep; eyes small, not retractile. 



Basal segment of antenna strongly produced forward and broadly 

 in contact with anterior margin of carapace, with movable segments far 

 removed from orbit ; produced inward and, together with outer margin 

 of antennule, forming a complete suborbital margin. Movable segments 

 small ; flagellum shorter than carapace, its articles elongate. 



