326 TJniversity of California Puhlicatioits in Zoology. [Vol.8 



bag is supported in a horizontal position and the net itself is 

 easily removed from the frame for emptying the catches. 



The bag of the net (pis. 22 and 23) is a simple cone of silk 

 bolting cloth held in a horizontal position, with detachable bucket 

 of brass at the truncated tip and head-piece of heavy linen. The 

 jaws which form the rim about the opening of the net stand in a 

 vertical plane when open. The two jaws {wp. j. and I. j., pi. 2-4, 

 tig. 5) are of semicircular form and are bevelled so as to close 

 tightly on the bevelled surfaces (hev.) and rotate on a horizontal 

 axle (ax.) which is enclosed in each of the hubs in the frame. 



THE NET FRAME 



The frame (pis. 22 and 23) is a massive casting of phosphor- 

 bronze, of circular form with enlargements at the horizontal axis 

 for the reception of the hubs of the jaws of the net. It widens 

 on the lower edge to a square foot which bears a recessed groove 

 for the reception of the accessory weight. The upper end of the 

 frame is expanded into a round head-piece or pedestal from 

 which project the pins of the trips and within which their 

 mechanism is protected. Its rear face (pi. 23, fig. 4) bears a 

 slotted lug {lug, pi. 25, fig. 15) in which the rods supporting 

 the net (n. sup.) and accumulator support (ace. sup.) are hinged. 

 Between the four projections upon the frame its outer surface 

 bears a low rib, so that in cross-section it is low T-shaped, to 

 insure rigidity when heavy weights are attached below. The 

 front of each recessed chamber which receives the hub is closed 

 by a hinged door {d., pi. 24, fig. 6, compare also figs. 3 and 4) 

 locked in place by hinged thumb-bolt {tJi. h.) which binds the 

 bearing (hear.) on the inner concave face of the door against the 

 machined outer surface of the cylindrical hub {huh) of the jaw 

 of the net, and thus holds it rigidly in place, but allows freedom 

 of rotation. 



The steel dredging cable (c, pi. 25, fig. 15), a % inch plow- 

 steel cable on the "Alexander Agassiz, " with terminal eye 

 adapted to all types of deep-sea apparatus, emerges from the 

 vertical axis of the net. The perfect balance of the net in a 

 vertical position is regulated in part by the lower flatiron-shaped 



