THE FLORA OF MOUNT HAL(M)N. 253 



considered by Dr. I^J. B. (Jopeland undci- the title I'lcrido/ikyta Halco- 

 nenses."' '2(H\ .species and varieties being I'epresented in the collection, of 

 whicli twenty were described as new, and eight reported for the (irst 

 time froin tlie Archipelago. Of tlie Orch'uJaccd- of the Halcon area, 

 101 species are known of which about 4"^ are new. 'Pliese were all sent 

 to Mr. OaJi-cs Ames and are considered by him in a following paper. 

 Tlie mosses collected on the expedition have been enumerated by V. F. 

 Ih-uthcrux, Ilelsingfors, Finland, his paper also following this one. No 

 attempt has been made to determine the rather extensive collections of 

 scale-mosses, lichens and fungi collected on the expedition, but it is hoped 

 that arrangements can be perfected with various specialists which will 

 result in having these gronps considered at a later date. Nearly all the 

 other material collected Ijy JMr. Merrill and myself has been discussed 

 in the present paper, but in one or two families, scantily represented 

 on Halcon, specific identifications have not been made for one reason or 

 another, and at least three species are not mentioned in this pajier, the 

 material representing them Ijcing insufficient to refer them with certainty 

 to their respective genera. 



Halcon is perhaps the most humid mountain in the I'hilippines, 

 the rainy season continuing practically for nine months of the year, 

 from IMay to January, without interruption, while the remaining three 

 months are by no means free from precipitation, as we know from 

 Lieutenant Lee's experience in the vicinity of Halcon in April, 1904. 

 The enormous amount of rain in the Halcon area is shown by the rela- 

 tively very large rivers flowing from the range. Although these in the 

 maximum are not more than 25 or 30 miles in length, and perhaps they 

 may be shorter, they have a breadth of from 100 to 300 yards in theii' 

 lower parts, and a constant flow of a large volume of water. In the 

 rainy season the volume of the latter is greatly augmented, all the rivers 

 being subject to sudden and enormous floods, as is shown by the expe- 

 rience of Whitehead, Lee and our own party. Whitehead recorded that 

 the Catuyran Eiver, 200 yards wide at the place where his camp was 

 located, rose over 20 feet within a period of less than twelve hours. 



Epiphytic orchids, ferns and other plants, mosses, lichens, etc., which in 

 other parts of the Philippines are usually found only at considerable alti- 

 tudes above the sea, are in the vicinity of Halcon encountered at compara- 

 tively low elevations, along the Alag and Binabay Elvers, 65 to 200 meters 

 above sea level, and along the Baco Eiver at approximately sea level, 

 thus showing that the relatively high humidity is not confined to Halcon 

 itself but affects the surrounding low country to a considerable extent. 

 As a result of this high humidity the open grass lands and savannah 

 -forests are entirely wanting on the north side of the Halcon Eange, 



"^This .Jounial, See. (', Bol . (1B07). 2, 11!)-151. 



