OPHIURANS OF THE PHILIPPINE AND ADJACENT WATERS. 235 



which leave naked a considerable part of their surface. The upper 

 arm plates have the typical form (pi. 31, fig. 2, and pi. 33, fig. 13). 



I show here another specimen of Ophiothrix hirsuta from my own 

 collection which comes from the Keel Sea in which the radial shields 

 are very much more extensively covered than in the Albatross in- 

 dividual (pi. 31, fig. 1). 



The club spines of the dorsal surface of the disk are usually thick 

 and stout (pi. 99, fig. 2a) and conical in form, and they terminate 

 in thick points the number of which varies from four to six. At 

 some distance from the disk the first ventral arm spine transforms 

 into a hook with three or four branches of the form which is most 

 commonly seen in the genus Ophiothrix (fig. 26), that is to say, 

 with the terminal point very stout, the second much weaker, and 

 the third or the two following still weaker. This form is different 

 from that which I have shown in O. galatheae and from that 

 which we find in O. longipeda and O. puncto-limbata. I show (c) 

 the forms taken by the first ventral arm spine before its complete 

 transformation into a hook. The rounded or oval tentacle scale ends 

 in a point, sometimes single, sometimes accompanied by one or two 

 others very much smaller (d). 



Ophiothrix hirsuta is very widely spread throughout the whole 

 Indo-Pacific region. 



OPHIOTHRIX LONGIPEDA (Lamarck). 



Plate 31, figs. 3, 4; plate 33, figs. 9, 10; plate 100, fig. 2. 



See for bibliography : 

 Ophiothrix longipeda Kcehlee ('05), p. 92; ('07), p. 334; ('07b), p. 

 252.— H. L. Clark ('08), p. 298.— Kcehler ('10), p. 294.— H. L. Clakk 

 ('15), p. 274; ('15a), p. 90.— Matsumoto ('17), p. 227. 



Localities. — Albatross station 5179; vicinity of Eomblon; Romblon 

 light bearing S. 56° E., 8.36 kilometers (4.50 miles) distant (lat. 

 12° 38' 15" N., long. 122° 12' 30" E.) ; 68 meters (37 fathoms) ; 

 March 25, 1908 ; hrd. S. 



One specimen (Cat. No. E. 334, U.S.N.M.). 



Albatross station 5249; Gulf of Davao; Lanang Point bearing N. 

 1.85 kilometers (1 mile) distant (lat. 7° 06' 06" N., long. 125° 40' 

 08" E.) ; 42 meters (23 fathoms) ; May 18, 1908; Co., S. 



Two specimens (Cat. Nos. E. 336, E. 365, U.S.N.M.). 



Albatross station 5401; north of Cebu; Tanguingui Island Light 

 bearing N. 79° W., 42.62 kilometers (23 miles) distant (lat. 11° 

 24' 45" N., long. 124° 06' 00" E.) ; 54 meters (30 fathoms) ; March 

 16, 1909; fne. S. 



One arm (Cat. No. 41072, U.S.N.M.). 



Albatross station 5524; northern Mindanao and vicinity; Point 

 Tagolo Light bearing S. 34° W., 31.50 kilometers (17 miles) distant 



