PART 1 GARTH : PACIFIC OXYRHYNCHA 395 



Ham N. Smith II. Ovigerous specimens were also collected by Elinor D. 

 Robson at Changame, Panama, in May. 



Remarks: Prior to the publication of the Zaca Expedition report 

 (Crane, 1947), which recorded its occurrence at Port Parker and Uvita 

 Bay, Costa Rica, and Bahia Honda, Panama, Microphrys platysoma 

 had not been recorded between Mazatlan, Mexico, and Taboga Island, 

 Panama. The Zaca obtained M. platysoma at Clarion, the Velero III at 

 Socorro Island of the Revilla Gigedo group. Specimens from Socorro 

 Island and the Galapagos Islands are alike in having the branchial spines 

 reduced to inconspicuous tubercles, emphasizing the roundness of the 

 branchial regions. There is no reason, however, for considering them 

 distinct from the mainland stock. A specimen from 10 miles W of Pta. 

 Malarrimo, Bahia Sebastian Vizcaino, Lower California, is atypical in 

 having the spine of the basal antennal article slenderer, the outer bran- 

 chial spine shorter, and the outer marginal lobe of the basal antennal 

 article wanting. 



Microphrys triangulatus (Lockington) 

 Plate W, Figs. 6, 9 ; Plate 43, Fig. 4 



Mithraculus triangulatus Lockington, 1877c, p. 73. 

 Mithrax triangulatus, Kingsley, 1879a, p. 149. Miers, 1886, p. 86. 

 Microphrys triangulatus, Rathbun, 1898, p. 578; 1923b, p. 635; 1925, 

 p. 505, pi. 177, text-fig. 145. Boone, 1927, p. 171, fig. 56. Garth, 

 1946, p. 403, pi. 63, fig. 6. 

 Microphrys hranchialis, Rathbun, 1902b, p. 285. (Not M. hranchialis 

 Rathbun, 1898.) 



Type: "Several specimens, both sexes," originally deposited in the 

 collection of the California Academy of Sciences, no longer extant ; male 

 length 16 mm, width 14 mm, female length 13.5 mm, width 12 mm. 



Type locality: Gulf of California; W. J. Fisher, collector. 



Localities subsequently reported, ivith collectors: Gulf of California, 

 Mexico: Agua Verde Bay and San Josef [Jose] Island, Albatross (Rath- 

 bun, 1923b) ; off La Paz Bay, 7-8 fathoms, and off Cerralvo Island, 

 9.5-10 fathoms, Albatross (Rathbun, 1898). Galapagos Islands, Ecua- 

 dor: Albemarle Island, 12 fathoms, Hopkins-Stanford Expedition 

 (Rathbun, 1902b, as Microphrys branchialis) ; Charles, Indefatigable, 

 James, Chatham, and Hood Islands, 0-40 fathoms, Velero HI (Garth). 



Atlantic analogue: None. 



Diagnosis: Carapace nearly smooth, anterior branchial regions greatly 

 swollen, spine at lateral angle blunt and conical. Hepatic margins with- 



