OPHIURANS OF THE PHILIPPINE AND ADJACENT WATERS. 163 

 AMPHIPHOLIS KOCHII Liitken. 



Plate 70, tigs. 1-3. 



Amphipholis Jcochii Lutken ('72), p. 10, pis. 1 and 2, fig. 6.— Lyman ('82), 

 p. 146.— Matsumoto ('17), p. 192, fig. 52. 



Locality. — Hakodate. Japan. 



One specimen. 



Notes. — The specimen is unfortunately incomplete, and the whole 

 dorsal surface of the disk is torn away ; the arms also are not pre- 

 served for their full length; they must be rather long, and two of 

 them are preserved, respectively, for a length of 4 mm. and 6 mm. 



I had at first some hesitation in referring my specimen to A. kochii, 

 for it differs from Liitken's description and figures by a slight varia- 

 tion in the form of the mouth shields ; but all the other characters are 

 well enough in agreement to permit this determination. The speci- 

 men shows the following features: 



The mouth shields are large, longer than broad, pyriform, with 

 the proximal angle somewhat rounded and the two sides slightly 

 convex, passing over rounded angles to the distal border; this last 

 is convex, and shows in the middle a small lobe which projects into 

 the interradial space. The adoral plates, which are of medium size, 

 are narrowed inwardly, but they are in contact in the median inter- 

 radial line; they broaden outwardly and send off a process which 

 separates the mouth shield from the first side arm plate. The oral 

 plates are rather high and narrow. The proximal mouth papilla is 

 elongated, rather thick, cylindrical, and twice as long as broad; the 

 second is small, short, almost as long as broad, with the free border 

 rounded ; the third or external papilla is very broad, squamiform, 

 twice as long as broad, with the free border rounded. 



The upper arm plates are very large, and especially extremely 

 broad ; they cover almost the entire dorsal surface of the arms, only 

 leaving a very small and very narrow triangular space for the side 

 arm plates. The proximal border is broad and convex, or better, it 

 is formed by two sides which are united by a very obtuse and rounded 

 angle; the distal border is straight or slightly concave; the sides are 

 very short, strongly rounded, passing over by also very rounded 

 angles to the two long sides. All these plates are in contact. Very 

 many of the dorsal plates in the proximal region of the arms are 

 divided into two by a longitudinal or somewhat oblique groove which 

 is usually found near the middle. 



The first under arm plate, which is narrowed by the neighboring 

 external mouth papillae, is very small and triangular, with the apex 

 proximal. The others are large, pentagonal, broader than long, with a 

 very obtuse proximal angle bounded by two straight sides; their dis- 



