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-GHOGRAPHICAL AND BATHYMETRICAL DISTRIBUTION. 
We do not yet possess the data necessary for a complete exposition of the geoeraphi- 
cal distribution of the Plumularidxe. It may be generally asserted of this group that it 
attains its greatest development in the warmer seas of both hemispheres, and that in 
tropical and sub-tropical regions it has its maximum in multiplicity of form, in the size 
of the colonies, and in individual profusion. 
The dredgings of the Challenger and of the United States Exploration of the Gulf 
Stream would further seem to point to two centres of maximum development within the 
area thus indicated,—an eastern centre, which is situated in the warm seas around the 
Philippines and other islands of the East Indian Archipelago, and a western centre, 
which will be found in those which lie around the West Indian Islands, and bathe the 
eastern shores of Central and Equinoctial America. From these two centres the largest 
known Plumularian colonies have been obtained, and we learn, on the authority of 
Semper, that the natives of the Philippine Islands regard with dread, in consequence of 
their formidable stinging powers, some of the great Plumularians which occur around 
their shores. | 
These eastern and western centres of Plumularian distribution remind us of the two 
great centres in which the Cheiroptera have their maximum development, as scen in the 
gigantic bats of both hemispheres,—centres of Cheiropteran distribution which are nearly 
coincident with these regions of maximum development in the Plumularidee. 
In bathymetrical distribution the Plumularidee present considerable variation. 
Among the species described in the present Report some are quite littoral, having been 
dredged from depths ranging between 8 and 20 fathoms. The greater number however 
of the Challenger species have been obtained from depths between 20 and 150 fathoms, 
while the dredge has brought up three species, Aglaophenia filicula, Aglaophenia acacia, 
and Polyplumaria pumila, from a depth of 450 fathoms. The striking and beautiful 
genus Cladocarpus consists of eminently deep water forms, and of the two species here 
described one, Cladocarpus formosus, was obtained in the Japan Seas from a depth 
varying between 420 and 775 fathoms—the same species having been dredged by the 
“Porcupine ” in the seas lying to the north of Scotland from 167, 560, and 632 fathoms 
—while Cladocarpus pectiniferus was dredged by the Challenger off the Azores from 900 
fathoms. This last is the greatest depth from which any Plumularidan is known to have 
been obtained, 
