PART 1 GARTH I PACIFIC OXYRHYNCHA 393 



W. J. Fisher (Lockington, as Pisoidesf celatus) ; La Paz Bay, L. Diguet 

 (Rathbun, 1925; these are in all probability the specimens reported ear- 

 lier by Bouvier without precise locality). Revilla Gigedo Islands, Mex- 

 ico: Clarion Island, Zaca (Crane, 1947). Mazatlan, Mexico, A. Agassiz 

 (Rathbun, 1925). Costa Rica: Port Parker and Uvita Bay, Zaca (Crane, 

 1947). Panama: Bahia Honda, Zaca (Crane, 1947); Taboga Island, 

 J. Zetek, and Panama Bay, Meek and Hildebrand (Rathbun, 1925). 

 Colombia: Gorgona Island, Askoy (Garth, 1948). Ecuador: Galapagos 

 Islands: Tower Island, 40-70 fathoms, Velero III (Garth, 1946). 



Atlantic analogue: Microphrys antillensis Rathbun. 



Diagnosis: Carapace much longer than broad, granules many; two 

 spines in a transverse line at widest part of branchial region. Lateral 

 lobes rimmed or collared. Margin of basal antennal article with an outer 

 lobe. Male first pleopod with keel rounded and well separated from 

 triangular, pointed tip. 



Description: Carapace depressed, tuberculate and granulate; areole 

 at inner angle of branchial region very finely granulate ; two laminiform 

 processes on the anterolateral wall, one on the hepatic region, the other 

 on the branchial region, the latter not projecting in an imbricated man- 

 ner. Surface of hepatic process in one plane, with the anterior end acute 

 and projecting forward ; sometimes at the middle of the upper edge a 

 tubercle which projects outward. A spine between the hepatic and bran- 

 chial processes and below their level ; two branchial spines, one on the 

 posterolateral angle and the other farther in but on the same transverse 

 line. On the posterior margin a row of tubercles increasing in size toward 

 the middle, those of the middle pair larger than the others. Rostral horns 

 slender, directed forward, about one-sixth the length of rest of carapace. 

 Antennal spines about half the length of rostral spines ; the margin of the 

 antennal segment behind the spine curving outward, forming a shallow 

 lobe; preocular spines acute, half the length of antennal spines. 



Arm with a dentate, laminate superior crest ; wrist tuberculate ; palm 

 less than twice as long as broad ; fingers widely gaping, the pollex being 

 strongly curved downward. Legs sparsely hairy and with a few spines 

 and tubercles ; propodal segments with a prominent rounded distal lamini- 

 form process for articulation of dactylus. (Rathbun, 1925, modified) 



Material examined: 93 specimens from 35 stations. (See Table 81) 

 From 10 miles W of Pta. Malarrimo, Lower California, and Puerto 

 Refugio, Angel de la Guarda Island, Gulf of California, Mexico, to 

 Punta Santa Elena, Ecuador, and including Socorro Island of the Revilla 

 Gigedo group. 



