68 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



bottom samples at depths from 1490 to 2845 fathoms iu the track of 

 the great Peruvian current formed a true infusorial earth. 



The tow nets also contained many species of Hyalea, Cymbulia, 

 Styliola, Cleodora, Tiedemannia, Clio, and the like. On one occasion 

 the mass of the pelagic hauls consisted entirely of small brown 

 Copepods, the contents of the tow nets looking like sago soup. Another 

 time Sagittae, Salpae, Doliolum and Liriope, all most transparent forms, 

 formed the bulk of the tow net's catch. Again, Firoloides and 

 Carinarias constituted the bulk of the haul. These catches, coming 

 on successive days or interrupted with hauls of more than mediocre 

 quality, show how hopeless it is at sea to make any quantitative analysis 

 of the pelagic fauna and flora at any one station within the influence of 

 such a great oceanic current as the Chilian and Peruvian stream. 



Hauls of the trawl made at the western extremity of our lines 

 brought us within the area of the manganese nodules, with its radiolarian 

 ooze mud, shark's teeth, Cetacean ear-bones and beaks of Cephalopods ; 

 nothing could stand the damaging work of these uodules in grinding to 

 pieces all the animal life the trawl may have obtained. Down to the depth 

 of 2200 fathoms or so the bottom was covered by Globigerina ooze, its 

 character being more or less hidden when near tlie coast by the amount 

 of detrital matter and terrigenous deposits which have drifted out to sea. 



North of the Galapagos we found vegetable matter at nearly all the 

 stations, and between the Galapagos and Callao such material was not 

 uncommon in the trawl. 



Beyond the line of 2200 fathoms dead Eadiolarians became quite 

 abundant on the bottom, as well as in the mud of the manganese no- 

 dules, thoujjh among; the nodules it was not uncommon to find an occasional 

 Biloculina, Many of the dead Radiolarians found on the bottom Professor 

 Kofoid found in the guts of Salpae swiniming near the surface or witliiu 

 the 300-fathom line in the tow nets sent to that depth. The same is 

 the case with many of the Dinoflagellata which had been considered as 

 deep-sea types. In our tow nets from 300 fathoms we found very com- 

 monly Tuscarora, Tuscarosa, Aulospira, and others. In depths of 300 

 fathoms to the surface the tow net was rich in Tintinnidae, either dead 

 or moribund Planktoniellae, and Dinoflagellata. Among the Dinoflagel- 

 lata there were 10 species of Ceratium, 9 of Peridinidae, Gonyaulax, 

 Phalacroma, Pyrocystis, Cyttarocylis, Undella, and Dictiocystus. On tlie 

 surface Planktoniella sol predominates with Asteromphale, Biddulphia, 

 and Synidia thalassothrix ; among the Dinoflagellata we obtained 12 

 species of Cei'atium, 5 of Peridiuium, and 22 species of other Peredinidae. 



