MUSEUM OF COMPARATIVE ZOOLOGY. 199 



at a depth of 175 fathoms, and after towing for about twenty minutes 

 sent the messenger to close it. On examining the bottom part of the 

 net, which came up tightly closed, we found it to contain practically the 

 same things as we obtained in the surface net at the same spot. 



On two occasions we sent the net to be towed at deptbs of 800 

 fathoms and of 700 fathoms, the depths at these points being in one 

 case 905 fathoms and in the other 773 fathoms. At the greater depth, 

 the water shoaled somewhat while towing, as the closed part of the net 

 came up partly filled with fine silt; while during the second haul, the 

 twisting of the swivel wound the straps of the weights round the rope, 

 and the net came up open, but must have dragged very close to the 

 bottom, as it contained a fine specimen of Xettastoma, and some Pense- 

 ids, which we supposed to be deep-sea types. Otherwise the net con- 

 tained only the customary surface species of Sagitta, Pteropods, Copepods, 

 Schizopods, Tunicates, and Fishes. These two hauls were made about 

 the middle of the Gulf of California, at a distance of some fifty miles 

 in a southwesterly direction from Guaymas. 



On the 23d of April, a few hours before reaching Guaymas, we made 

 one more attempt with the Tanner tow-net, at a depth of 620 fathoms, 

 sending the net to be towed at a depth of from 500 to 570 fathoms. 

 We found in this case in the bottom part of the net, which came up 

 tightly closed, a Scopelus, a Penseid, and a Hyalea, while the upper 

 open part of the net contained the same surface species we had obtained 

 before. 



My experience in the Gulf of California with the Tanner self-closing 

 net would seem to indicate that in a comparatively closed sea, at a 

 small distance from the land, there may be a mixture of the surface 

 species with the deep-sea bottom species, a condition of things which 

 certainly does not exist at sea in an oceanic basin at a great distance 

 from shore, where the surface pelagic fauna only descends to a com- 

 paratively small depth, about 200 fathoms, the limits of the depth at 

 which light and heat produce any considerable variation in the physical 

 condition of the water. The marked diminution in the number of spe- 

 cies below 200 fathoms agrees fairly with the results of the " National " 

 Expedition. 



The more I see of the "Albatross," the more I become convinced that 

 her true field is that of exploration. She is a remarkably fine sea boat, 

 and has ample accommodation for a staff of working specialists such as 

 would be needed on a distant expedition. The time will soon come 

 when the Fish Commission will hardly care to continue to run her, 



