228 



SCIENCE, 



[Vol. IV., No. 84. 



trawl can be safely used ; and here they per- 

 form a real service, notwithstanding the impos- 

 sibility of extricating the delicate specimens 



from the hempen swabs without injury. They 

 may also be employed on moderately rough 

 bottoms to supplement the work of the dredge ; 

 but, used separately, both have, b} T actual expe- 

 rience, been proved to obtain far better results. 

 On smooth bottoms, it does not seem rational 

 to suppose that the tangles can in any way add 

 to the results afforded by the beam-trawls, 

 properly managed ; and several trials, made on 

 rich ground of this character, have shown such 

 to be the case. 



A short distance beyond the coast-line, we 

 generally come upon such uniformly smooth 

 bottom,* that the beam-trawl can be trusted 

 nearly everywhere. Working in such a region 

 as this, enormous hauls would be obtained day 

 after day ; the trawl delivering its specimens in 

 exceptionally good condition, and affording the 

 full variety of life which existed there. Dur- 

 ing the earlier part of the explorations, alcohol 



was used at the rate of. two to three barrels a 

 day, and certainly better results could not 

 be asked for. At intervals the tangles would 

 be lowered, but they never furnished any 

 thing new ; and the pitiable condition of the 

 specimens they brought up, when compared 

 with those from the trawl, caused their use to 

 be discontinued. And what more could be 

 expected of them, when attached to the run- 

 ners or net of the trawl? 



The tangles devised by Professor Verrill, in 

 1871, were secured to a triangular iron frame, 

 similar to that of the rake-dredge. In 1873, 

 however, the} 7 were altered and improved as 

 represented in fig. 4. 



The3 T consist of an iron bar, rigidly attached 

 to two rings or wheels, as a framework, from 

 which extend several small iron chains, each 

 carrying from three to five hempen swabs of 

 medium size. The wheels are not intended to 

 revolve, but merely to keep the bar above the 

 ground, so as to prevent its coming in contact 

 with the specimens ; and whatever injury befalls 



jug. o. — Sig&bee's gravitating trap. 



the latter must result from their entanglement 

 among the hempen fibres. 



