Page:Popular Science Monthly Volume 66.djvu/565

Rh is stronger, by great 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 succeeding 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 hundreds 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, certain 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 latitude and longitude. Fortunately for this plan there had been recently 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 needs.