AGASSIZ: BAHAMAS. 9 



the lower part of the bag of the Tanner net, as long a haul through 

 water as the open part of the net would have to travel till it reached 

 the surface. This gave for comparison of their respective richness the 

 fauna of a horizontal column of water obtained in the closed part of the 

 Tanner net at one hundred, one hundred and fifty, two hundred and 

 fifty, and three hundred fathoms, of the same or of greater length than 

 the fauna of a vertical column from those points to the surface obtained 

 in the sweep of the open part of the Tanner net. 



In all our tows with the deep-sea self-closing Tanner net we took the 

 usual precautions of carefully filtering the sea water into which the con- 

 tents of the closed part of the net were emptied. We also made some 

 slight modifications in the construction of the Tanner net. Iron rods 

 were substituted for the rope guides of the pulleys, and one side was 

 loaded so as to cant the net while it was towed. Off Clifton, New Provi- 

 dence, we made some trials in the Tongue of the Ocean, at a distance of 

 not more than a mile from the edge of the bank, the depth being seven 

 hundred fathoms. "We towed at 9.30 a. m. in from one hundred to one 

 hundred and ten fathoms for about twenty minutes : the net closed suc- 

 cessfully. Only one Copepod was brought up from that depth, while in 

 the open part of the net we obtained several specimens of Eucope, many 

 bells of Diphyes, numerous Copepods, Alciope, Schizopods, larvae of Bra- 

 chiurans, Macrurans, Doliolum, Appendicularia, Gasteropod larvae, and 

 Collozoum. A fine Rbyzophysa came up attached to the wire after 

 hauling in forty fathoms. At 10.30 we took a second tow at three 

 hundred fathoms ; the closed part of the net contained nothing, and a 

 preliminary examination of the contents of the open part of the net, 

 which remained open from three hundred fathoms to the surface, showed 

 that it contained nothing we had not obtained from the shallower 

 depths between the surface and one hundred fathoms. 



In a haul with the deep-sea Tanner net, made at 1.50 p. m., five miles 

 off Havana, in a depth of seven hundred fathoms, we towed for twenty 

 minutes at a depth of three hundred fathoms. There was nothing found 

 in the closed part of the net. There was a strong southeast breeze, so 

 that we obtained comparatively little in the surface tow-net except a few 

 pelagic algae, Diphyes bells, and Copepods, while in the part of the 

 tow-net -which remained open all the way from the 300 fathom line to 

 the surface we brought up a mass of pelagic stuff, consisting of Cteno- 

 phores (probably species of Idyopsis and Eucharis), of two species of 

 Diphyes, of floats and tasters of Rhyzophysa, of masses of Copepods, of 

 Schizopods, three species of Salpae, many specimens of Doliolum, a few 



