analysis of their density and distribution. The following accounts should thus be considered open to serious question, but are the "best guess" at the present time. Leach Petrel (Oceanodroma leucorhoa): 380. Fifteen percent of all birds identified as this species belonged to the dark-rumped form (Soccorro Petrel). The species as a whole was most abundant in coastal waters near their breeding islands, but individuals were found scattered throughout the entire area. Soccorro Petrels had a second area of concentration from 03°S to 15°N along Longitude 097.5°W. A large number (85+) of "white-rumped storm petrels" in this latter area may have been this species or might have been Galapagos Petrels (Oceanodroma tethys) or Harcourt Petrels (Oceanodroma castro). Harcourt Petrel (Oceanodroma castro): 46. Apparently most abundant in the South Equatorial Current, but probably present in small numbers at least to 10°N. The collection of one specimen at 00°54"N by 097°31'W confirms their presence in this area. Sooty Petrel (Oceanodroma markhami): 9. These birds were observed only along Longitude 097.5°W between 07° and 13.5°N. In color and shape they appeared identical to Soccorro Petrels, but their flight pattern was more erratic and they were almost twice as large. Ashy Petrel (Oceanodroma homochroa): 31. Found only in coastal waters off of central Baja California. Black-Petrel (Loomelania melania): 36. Coastal waters of Baja California and Mexico from 20° to 25°N. Least Petrel (Halocyptena microsoma): 9. Most abundant in the general area of Guadalupe Island, although two birds were found at sea between 12.6° and 15.7°N. Wilson/Elliot Petrel (Oceanites oceanicus/gracilis): 4. All found within the warmer western waters of the South Equatorial Current. White-throated Letrel (Nesofregetta albigularis): 33. Found throughout the South Equatorial Current, but most abundant in the colder eastern area. White-bellied Petrel (Fregetta grallaria): 1. This bird had a well defined dark throat and pure white belly. It was observed at 01°42'N by 104°41'W. White-faced Petrel (Pelagodroma marina): 1?. One brief sighting of a bird which might have been this species occurred at 07°16'N by 118°31'W.