12 



SUPPLEMENT. 



to open it (time occupied 45"), and the cylinder traveled from 100 to 150 

 fathoms (time 45"), so as to collect the animal life to be obtained between 

 these limits. On drawing up the cylinder and washing out the sieve of 

 the trap, not only did we find that the water contained nothing different 

 from what had been brought up by the cylinder from the lesser depth, 

 but it did not contain even a single Radiolarian. 



"On the 15th of July, in Lat. 34° 28' 25" N., Long. 75° 22' 50" W., we 

 tried the Sigsbee cylinder for a third time, in a depth of 1,632 fathoms. 

 With the same precautions before and after using it, the cylinder was 

 sent to collect first between 5 and 50 fathoms (time 30"). The surface 

 was somewhat ruffled, and but little was found on the surface beyond a 

 few Crustacean larvae and Heteropods. The cylinder contained Hydroids, 

 fragments of Siphonophores, pelagic Alga?, Crustacean larvae, and Hetero- 

 pod eggs; forms which differed from these scooped at the surface, but 

 were identical with the species found on previous days at the surface 

 under more favorable surface conditions of the sea. Next, the cylinder 

 was arranged to collect between 50 and 100 fathoms (time of messenger 

 21" from surface to 50 fathoms, time of cylinder 40" to stopper from 50 to 

 100 fathoms). The water was found to contain only a couple of Squilla? 

 larva?, similar to those fished up at the surface. The third time the cylin- 

 der went down at this station it was lowered to collect from 100 to 150 

 fathoms (time of messenger from surface to 100 fathoms 45", time of 

 cylinder in passing from 100 to 150 fathoms 45"). The water when ex- 

 amined contained nothing. No Radiolarians were found at this station, 

 either at the surface or at any depth to which the cylinder was sent (150 

 fathoms). 



"The above experiments appear to prove conclusively that the sur- 

 face fauna of the sea is really limited to a comparatively narrow belt in 

 depth, and that there is no intermediate belt, so to speak, of animal life, 

 between those living on the bottom, or close to it, and the surface pelagic 

 fauna. 



"The experiments of using the tow-net at great depths (of 500 and 

 1,000 fathoms), as was done by Mr. Murray on the 'Challenger,' were 

 not conclusive, as I have already pointed out on a former occasion, while 



