OPHIURANS OF THE PHILIPPINE AND ADJACENT WATERS. 193 



about twice as long as the ventral, which is equal in length to the 

 segment; this is as H. L. Clark describes it in specimens in which 

 the disk has a diameter of 5 mm. However, in one of his specimens 

 in which the diameter of the disk reaches 6 mm., and which is the 

 largest of all, H. L. Clark noticed that the dorsal arm spine is shorter, 

 but he does not specify what its exact length is and whether or not it 

 is equal to the other two. From this observation the inference is that 

 in the specimens studied by H. L. Clark there are certain variations 

 in the relative dimensions of this dorsal arm spine, and as the only 

 difference which I can find between the descriptions and the figures 

 of O. pteropoma and O. profundi consists in the relative length of 

 the dorsal arm spine, I do not believe that it is possible to maintain 

 a distinction between the two species. The first name, having prior- 

 ity, should therefore alone be conserved. 



H. L. Clark has not discussed the comparative characters of 0. 

 pteropoma and he does not refer in any way to its affinities with 

 O. profundi. 



As may be seen from the photograph which I reproduce on plate 

 03 as figure 8, the dorsal arm spine is a little longer than the two 

 others, but it is less thick than the central spine ; Liitken and Morten- 

 sen say that in O. profundi the median spine is the stoutest. 



The color of the two specimens from station 5522 is pink ; the two 

 others are a grayish white. 



Ophiactis profundi was captured at depths of 1,008 and 1,644 

 meters (551 and 899 fathoms), between 0° and 4° N. latitude and 81° 

 and 90° W. longitude. Ophiactis pteropoma H. L. Clark was based 

 upon eight specimens, all with six arms, dredged in the Japanese seas 

 between 349 and 463 meters (191 and 253 fathoms). I have myself 

 recorded the occurrence of O. profundi, or of a form extremely close 

 to it, in the Atlantic, which was found by the Princesse- Alice at a 

 depth of from 214 to 650 meters (122 to 355 fathoms) in 36° N. lati- 

 tude and 31° W. longitude (Kcehler '09, p. 173). 



Matsumoto ('17, p. 154) believes that O. pteropoma is extremely 

 close to O. profundi, from which it only differs in having the arm 

 spines unequal instead of being subequal. 



OPHIACTIS SAVIGNYI Miiller and Troschel. 



Plate 64, figs. 5, 6 ; plate 96, fig. 2. 



See for bibliography : 



Ophiactis savignyi Kcehlee ('05), p. 26; ('05a), p. 1S4; ('13), p. 351; 

 ('14), p. 41; ('14a), p. 184.— H. L. Clakk ('15), p. 265; ('15a), p. 

 90.— Matsumoto ('17), p. 158. 



Localities. — Albatross station 5123; east coast of Mindoro; Mala- 

 brigo Light bearing N. 44° W., 60.23 kilometers (32.5 miles) dis- 

 55269— 22— Bui. 100 13 



