OPHIURANS OF THE PHILIPPINE AND ADJACENT WATERS. 345 



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in which the diameter of the disk was 25 mm. ; this species, to which 

 I gave the name of Pectinura modesta, possessed five arm spines, the 

 ventral spine being appreciably larger than the others, in this last 

 character recalling Lyman's P. tessellata. The specimen, unfor- 

 tunately unique, came from a locality very near that where R. con- 

 spicua had been found (7 S. latitude and 114 E. longitude, at a 

 depth of 330 meters, or 180 fathoms). 



Under the name of Pectinura elata I also described in 1907 a spe- 

 cies collected b}' the expeditions of the Travailleur and the Talisman 

 in localities widely different from the preceding (lat. 25 N., long. 

 19 W. ) at a depth of from 2,325 to 2.518 meters (1,273 to 1,380 fath- 

 oms) ; this ophiuran, w y hich was of rather large size, the diameter of 

 the disk exceeding 30 mm., was, like P. modesta, without ventral 

 pores. I characterized P. elata by the presence of three arm spines 

 which are less than half the arm segment in length, by having the 

 mouth shields as long as broad, and by the presence of a single ten- 

 tacle scale to each pore, this tentacle scale reaching a very large size 

 on the first arm segments. The affinities of this species seemed to me 

 especially toward P. heros Lyman, but it is distinguished from that 

 species by having the mouth shields as long as broad, by the large 

 size of the tentacle scales on the first arm segments, and by having the 

 arm spines larger on the first segments. 



But I find in the Albatross collection a large series of specimens 

 showing characters so variable, or rather showing in such a complete 

 manner all the intermediates between the different characters upon 

 which I had thought it possible t'o base a distinction between the three 

 species which I have just mentioned B . conspicua, B. modesta, and B- 

 elata that it does not seem to me possible to maintain the two latter. 

 I shall go even further and add that Lyman's P. heros and P. tesse- 

 lata, Atlantic species like B. elata. should probably not be separated 

 from B. conspicua, which thus ceases to be peculiar to the Indo-Pa- 

 cific region. I do not dare, however, to make a definite statement con- 

 cerning these two species, which I have not personally examined. 



To summarize the observations which I made on the specimens 

 collected by the Albatross, I shall record briefly the notes which 

 made, considering successively the size of the specimens, the shape of 

 the mouth shields, and the occurrence of a supplementary plate be- 

 yond the latter, the tentacle scales, the ventral pores, and the number 

 and dimensions of the arm spines. 



Regarding the dimension of the specimens, it may be said that all 

 sizes are represented, since the diameter of the disk measures in the 

 smallest 11 mm. (station 5114), while in the largest it reaches 45 mm.. 



