METHODS OF CAPTUEE 21 



are, however, unstinted riches of natural history which 

 the ordinary student may obtain with comparatively simple 

 means. By the use of the towing-net from a boat, espe- 

 cially after sunset in warm and calm weather, numerous 

 larval forms of Crustacea are to be obtained, as well as 

 adult forms of various orders. By dredging in a few 

 fathoms, or even in a few feet, of water, species enough 

 to occupy weeks and months of study may often readily 

 be secured. For this work sheltered bays and inlets 

 are favourable. "When the dredge brings up apparently 

 nothing but rugged pebbles and the worn shells of departed 

 molluscs, these are not to be despised. Among them may 

 be found the little crabs of the genus Ehalia, at the first 

 glance perhaps rejected as if pebbles themselves. Rare 

 Tan aids may come creeping out of the crevices of an old 

 oyster shell. When sea-weeds are brought up in the 

 dredge, they are not to be cast aside after a hasty exami- 

 nation as unproductive. They should be placed in a 

 vessel of shallow water, and, though the crafty inhabitants 

 lie close, they will eventually come forth. Sand and 

 muddy ooze scraped from the bottom requires to be passed 

 through a sieve or stirred about in a pailful of sea-water. 

 After the stirring, and before the animals have time to 

 regain the sand, the water must be poured off through a 

 muslin bag which will retain the desired specimens. Some 

 species, besides the edible ones, may be obtained by a sort 

 of systematic fishing. A dead crab, for instance, let down 

 in a lobster-pot, will attract one species or another accord- 

 ing to the locality, the clan trooping to the feast in hun- 

 dreds and thousands till they have consumed every par. 

 tide of the dainty repast. The voracity, indeed, of sotne 

 among the smaller Crustacea is such, and their numbers in 

 some places so enormous, that they have been known in a 

 single night to clear all the flesh ofi" a dead seal. To such 

 appetites almost any carrion is a sufiiciently alluring bait. 

 There is little need for surprise, under the circumstances, 

 at the label on certain museum specimens, intimating that 

 they were ' pulled off the head of a bear let down to the 

 bottom to be cleaned.' Some of the Amphipoda attack the 



