OPHIURANS OF THE PHILIPPINE AND ADJACENT WATERS. 263 



Notes. — Although Ophiothrix pusilla is easily recognizable, I have 

 thought it well to include two photographs of the specimen from sta- 

 tion 5249, which will supplement the figures published by Lyman and 

 by myself. 



The hook representing the first ventral arm spine has two or three 

 branches and does not show any distinctive character (pi. 101, fig. 

 86). The tentacle scale is very small, and terminates in a very long 

 point (fig. 8a). 



Ophiothrix pusilla is an essentially littoral species which has been 

 found in many localities in the Indo-Pacific region. The Siboga 

 dredged in the Sunda Archipelago at depths between 22 and 54 

 meters (12 to 30 fathoms). 



OPHIOTHRIX SIGNATA, new species. 



Plate 36, figs. 1, 2. 



Locality. — Albatross station 5140; vicinity of Jolo; Jolo Light 

 bearing S. 33° W., 11.30 kilometers (6.1 miles) distant (lat. 6° 08' 

 45" N., long. 121° 03' 00" E.) ; 139 meters (76 fathoms) ; February 

 14, 1908 ; fne. co. S. 



One specimen (Cat. No. 41069, U. S.N.M.) . 



Description. — The diameter of the disk is 11 mm. ; the arms are 

 unfortunately all broken off at the base and the longest is preserved 

 for a length of 17 mm. only. 



The disk is pentagonal. Between the radial shields, which are very 

 large, the dorsal surface shows numerous small, thickened, rounded 

 plates with a swollen surface ; each of these plates bears either a rather 

 elongated and cylindrical club spine ending in a few short, unequal, 

 and divergent spinules, or a true spine of greater or lesser length. 

 Intermediates of all types between the club spines and the true spines 

 may be found; the true spines are slender, provided with fine and 

 pointed denticulations, irregularly arranged, and their points usually 

 bear two or three small and very short spinules. The true spines are 

 especially found in the central region of the disk and in the inter- 

 radial spaces ; they disappear toward the periphery, where only club 

 spines occur; they are also absent from the radial spaces. These 

 spaces, which are very narrow, are occupied by two rows of plates 

 each of which bears its little club spine. At the periphery of the 

 disk the plates tend to separate from each other ; they are scarcely in 

 contact, and they begin to assume the characters which they show 

 on the ventral surface. The radial shields are very large, triangular, 

 very much longer than broad, and their length equals two-thirds the 

 radius of the disk. Their surface is naked except for a row of small 

 club spines near and parallel to their radial border. The two shields 

 of each pair are very close to each other, but they are never in con- 



