vni, D.6 Light: Philippine Alcyonana 439 



Silanga Channel between Taytay and Shark's Fin Bays, and 

 the Pabellones Islands). Because of its wide distribution in 

 the Islands and because it is so characteristic of the alcyonarian 

 fauna of the reefs of the Archipelago, I have given it the specific 

 name philippinensis. 



It is found growing on coral clumps and debris and on sand 

 and small stones on the reefs not ordinarily in such abundance 

 as certain species of the genus Nephthya, but forming a charac- 

 teristic part of the reef fauna, at a depth of from 1 to 3 meters. 

 On the reefs in the Silanga Channel it is the predominant 

 Nephthyid form. These reefs, which are very shallow and com- 

 posed of but few species of coral of such genera as Euphyllia, 

 Goniopora, and Astraeopora, seemed to be gradually dying, and 

 on the dead coral bases great numbers of colonies of this species 

 were found growing. It seemed to take the place of the reef 

 Nephthya which, so common on growing reefs, was practically 

 absent here.* When expanded it has the appearance of some 

 of the species of Nephthya, but the larger polyps and, the longer, 

 more slender, and more pointed tentacles give it a more open 

 and delicate appearance than that of the ordinary reef Nephthya. 

 On being disturbed a remarkable contraction of the entire colony 

 takes place, the colony contracting to one-third or one-fourth its 

 size when expanded. One who has seen only the contracted, 

 preserved specimens with their hard rigid appearance can have 

 but little idea of how delicate and graceful the expanded colony 

 is. Length, breadth, and the relative proportions of the parts of 

 the colony are very uncertain quantities in this species as they 

 differ greatly with the degree of contraction. 



There is so much variation in the form of the colony, the 

 branching, and the position and arrangement of the polyps that 

 I have found it necessary to distinguish three varieties of this 

 species. Typical specimens of these varieties are quite distinct 

 in general appearance and in certain characters; but the fact 

 that they are very similar in their spiculation, which seems to 

 be the most basic diagnostic character in this genus and the 

 fact that there are some specimens which seem to be connecting 

 links with the typical forms make it inadvisable to consider 

 them of specific rank. On the other hand, it would be very 

 inconvenient and confusing to place them all in a single un- 

 divided species. This division into varieties is tentative, as 

 I expect in the near future to undertake a study of the anatomy 

 of the species and varieties described in this paper with a 

 view to finding some additional diagnostic characters which 



