BERMUDA BIOLOGICAL STATION. 561 



is stronger, by giv.it yellowish or greenish patches of colonial actinians 

 (Palythoa) belonging to the Zoanthidae (Fig. 17). The upper end of 

 this bay is a swamp of mangroves (compare Fig. 18), on the branches 

 of which numbers of tree crabs (Goniopsis cruentatus) clamber about. 

 To catch these creatures requires some skill, two persons usually suc- 

 ceeding better than one, for the crab, when too closely pursued, quickly 

 drops to the ground, even from a height of ten or fifteen feet, and 

 escapes into a burrow, unless a net is dexterously interposed during his 

 descent. Along the edges of the tidal stream near the head of the bay 

 are found in great numbers prawns that are so transparent as to escape 

 observation until they move; they dart about with such swiftness that 

 it is difficult to take them in the net. 



When one cautiously approaches the edge of the cliffs that flank the 

 entrance to the bay and looks down on the hard, wave-beaten rocks 

 he sees large numbers of crabs that take alarm at the least motion 

 and scurry away to crevices, or scramble down into fairly deep water, 

 where with their sharp claws they are able to cling to the rough rocks 

 and make almost as good progress as in the air. On the platforms 

 and in. the niches of the rock between tide marks are congregated hun- 

 dreds of chitons {Chiton marmoreus), whose shells give proof of the 

 action of the waves, which are almost constantly dashing against them 

 at high water. 



In view of the possibility of the establishment of a permanent 

 station, it seemed desirable to keep records of the places where various 

 animals and plants were found. To this end each person was provided 

 with a note book, and to prevent duplication of locality numbers, cer- 

 tain locality numbers were assigned with each book. Whenever a' 

 party of individuals made collections together in a circumscribed area, 

 as in dredging, or in shore collecting at particular spots, the same 

 locality number was used by all. To enable future workers to find 

 the precise localities mentioned, these places were designated by lati- 

 tude and longitude. Fortunately for this plan there had been re- 

 cently published an Ordinance-Survey map of the Bermudas on a 

 scale of 880 feet to the inch, so that by ruling one of these maps with 

 rectangles ten seconds square it was possible to indicate on the map the 

 position of any locality to within a very few feet. 



A card catalogue embracing the names of all the animals and 

 plants arranged systematically will ultimately show, not only what 

 organisms, both living and fossil, are to be met with in the islands 

 and adjacent waters, but also the precise localities at which they have 

 been found, and the conditions under which they live. To this will 

 be added as rapidly as possible the periods of ovulation, etc., so that 

 one may not waste time in searching in the wrong place or at the 

 wrong time of year for the material one need-. 



