204 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



The Monaco Deep-sea Trap. 



The deep-sea trap which we employed was supplied by the United 

 States Bureau of Fisheries, and in all respects resembled the pattern of 

 the Prince of Monaco, except that the frame-work was constructed of 

 galvanized iron gas pipe instead of wood. The use of the Monaco 

 trap, like that of closing-nets, is difficult on a small vessel, but judg- 

 ing from the present Cruise the results which it may be expected to 

 yield are more than commensurate with the trouble involved. I ques- 

 tion, however, whether it possesses any superiority over the trawl, ex- 

 cept in certain special cases. The chief difficulty on a vessel so small 

 as the " Grampus " is the nature of the rope to be employed, if sets are to be 

 made in depths of 500 fathoms or upward. Under these circumstances the 

 five-eighths inch wire rope usually used in trawling is out of the question, 

 for not only is it difficult to handle, but its great weight in water would 

 require a float or buoy larger than could be carried. On the present 

 trip, having no smaller wire rope, hemp " buoy line " was successfully 

 employed ; but it has the drawback of weakness, while its great frictional 

 resistance to the water enormously increases the difficulty of hauling in 

 the trap with a small motor. No doubt a very small wire rope, with 

 breaking strain of about 800 pounds, would prove satisfactory. A larger 

 one is unnecessary, since the weight of trap and sinker together need not 

 exceed 100 pounds. The buoy should be provided with a flag of some sort 

 on a light pole. For economy of time it would be advisable to have 

 several traps and set them in lines ; with such an arrangement there 

 would be little danger of losing them, while the vessel might be em- 

 ployed with other work during the sets. For bait we used dead fish 

 and table scraps. 



In our two sets the results were as follows : at Station 3 the trap 

 remained on bottom about one hour only. It brought back two species 

 offish, i. e., eleven large Myxine glutinosa, and one Synapliobranckus pin- 

 7iatus, as well as several specimens each of two species of large amphipods. 

 At Station 12 the trap was on bottom for about two hours. It con- 

 tained one Synaphobranclius pinnatus, one Physis chesteri, and twenty-one 

 Simenchelys parasiticus. The latter species must be extremely abundant at 

 this locality, to allow so many to find their way into the trap in so short 

 a time, for they are but weak swimmers. 



