OPHIURANS OF THE PHILIPPINE AND ADJACENT WATERS. 161 

 AMPHIURA VADICOLA Matsumoto. 



Plate 65, figs. 1-5 ; plate 96, fig. 5. 



Amphivra vadicola Matsumoto ('15), p. 71 — H. L. Clark ('15), p. 235. 

 Ophionephthys phalerata Marktanner-Turneretscher ('87), p. 301 (not of 

 Lyman, 1874). 



Locality. — Otaru, Hokkaido, Japan. 



Six specimens (Cat. Nos. 41135, 41136, U.S.N.M.). 



Notes. — The specimens are in a very poor state of preservation; 

 the arms are broken into numerous fragments; they must be very 

 long and very much coiled, but also very fragile; the disks them- 

 selves are more or less distorted. Nevertheless the characters of the 

 species are perfectly recognizable ; they belong without doubt to the 

 old genus Ophionephthys, and agree absolutely with the form which 

 Matsumoto has recently described under the name of Amphiura 

 vadicola. 



The diameter of the disk is about 5 mm. ; the length of the arms 

 must exceed 100 mm. or 120 mm. The color of the specimens in alco- 

 hol is a brownish yellow. 



Amphiura vadicola was created by Matsumoto for a species which 

 is extremely common at Kagoshima ; it is the same ophiuran which 

 Marktanner had referred with some doubt to Ophionephthys phaler- 

 ata ('87, p. 301), but which is certainly different from Lyman's 

 species. Acording to Matsumoto, A. vadicola differs from O. phal- 

 erata in the larger radial shields, in the pentagonal and not oval 

 mouth shields, in having the adoral plates not in contact in the me- 

 dian interradial line, in the higher oral plates, in the contiguous 

 upper arm plates, and in having the arm spines not cylindrical, but 

 flattened; furthermore, the second ventral spine shows a very pecu- 

 liar form ; Matsumoto says that it is " spur-shaped," without more 

 definitely defining the outline. 



My specimens agree well with the description of A. vadicola given 

 by Matsumoto; but the form of the mouth shields is not exactly 

 pentagonal as described by the Japanese naturalist ; these shields also 

 are not oval and transversely broadened ; they have rather the form 

 of a triangle of which the base is proximal and the angles are very 

 rounded, with the sides almost equal. As for the adoral plates, they 

 conform to Matsumoto's description, and are not in contact by their 

 radial or external angle; they are merely very close together and 

 they inclose between them the first under arm plate which is narrow, 

 without forming a continuous circle, as Lyman has described in his 

 Ophionephthys phalerata. The radial shields are much elongated, 

 almost four times as long as broad, simply triangular, and not " pear- 

 seed shaped." The separation of the under arm plates varies a little 



55269— 22— Bui. 100 11 



