84 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



existence of the great plateau dividing Barker Basin along the South 

 American coast from Grey and Moser Basins to the west is most inter- 

 esting. It recalls the division of the southern Atlantic into an eastern 

 and western basin by a central connecting ridge (The Challenger Ridge). 

 The Albatross plateau joins the western extension of the Galapagos 

 plateau, as developed by the "Albatross" in 1891. 



The existence of a sounding of 2554 fathoms near the equator in 

 longitude 110° W. would seem to indicate a small basin included in this 

 plateau, disconnected from Grey's Deep and Moser Basin by its extension 

 to the west. How far west towards these basins that extension reaches, 

 no soundings indicate as yet. It is interesting to note that along the 

 Mexican coast there are a number of deep basins lying disconnected close 

 to the shore, just as there are a number of disconnected deeps close to 

 the South American coast extending from off Callao to off Caldera, Chili, 

 opposite high volcanoes or elevated chains of mountains. These basins 

 are deeper than the Albatross plateau to the south, and form a deep 

 channel separating in places the plateau from the steep continental 

 slope. The steepness of a great part of the Mexican continental shelf 

 is well seen, especially off Acapulco and Manzanilla. One of the small 

 basins along the Mexican coast with 2661 fathoms lies off Sebastian 

 Yiscaino Bay ; another with more than 2900 fathoms is to the west of 

 jNIanzanilla Bay ; a third to the southeast of Acapulco has about the 

 same depth, ^ and a fourth with 2500 fathoms is off San Jose, Guatemala. 

 These basins off the west coast, close to the shore and at the foot of a 

 steep continental slope, are in great contrast to the wide continental 

 shelves which characterize the east coast of Central America and the 

 east coast of the United States. 



The collections made during the present expedition will give ample 

 material for extensive monographs on the Holothurians, the siliceous 

 Sponges, the Cephalopods, the Jelly-fishes, the pelagic Crustacea, Worms 

 and Fishes of the eastern Pacific, as well as on the bottom deposits and 

 on the liadiolarians and Diuoflagellates, Diatoms, and other Protozoa 

 collected by the tow nets. Small collections of plants were made at 

 Easter Island and Manga Reva which may throw some light on the origin 

 and distribution of the flora of the eastern Pacific. 



1 Tlie List sounding we made off Acapulco in 2474 fathoms 29 miles south of the 

 Light House showed the western extension of this deep hole. 



