204 ART. 2. — H. MATSÜMOTO : 



Bering Sea. Alaska. Washington. 



AtnpJiiura iris Lyman. 



AmpJdura iris : Lyrian, Bull. Mus. Comp. Zool., VI, Pt. 2, 1879, p. 23, 

 PI. XI, figs. 302-304; Lyman, Hep. Clialleuger, V, 1882, p. 132, PL XVI, 

 fig. 4-G; Kœhlee, Exp. Siboga, XLV, Pt. 1, 1904, p. 81. 



One specimen ; Mera-out-Oisegaké ; Sagami Sea ; 300 fathoms. 

 Seven specimens; Okinosé (a submarine bank), Sagami Sea; 85 

 fathoms. 



Sagami Sea; 420-775 fathoms (Lyman). 



Malaysian waters; 1,595m. (Kœhlee). 



The first specimen, which is the largest, measures 5.5 mm. 

 across the disk and 25 mm. in the arm length. The disk scales 

 are fine, ill-defined, convex and pavement-like, so that the dorsal 

 surface of the disk appears rough. The radial shields are long, 

 narrow, bar-like, about half as long as the disk radius, about 

 four times as long as wide, completely separated from each other, 

 those of a pair almost parallel. The distal oral papilla is sub- 

 quadrangular, with truncated or indented free end. The apical 

 one is also squarish, but slightly smaller than the distal one. 

 The additional papilla, which corresponds to the scale of the first 

 oral tentacle pore, is also squarish, with truncated or indented 

 free end, smaller than the distal, but larger than the apical one. 

 The dorsal arm plates are rather oval and slightly in contact witli 

 one another ; the surface is convex both transversely and longi- 

 tudinally, so that the plate is more or less humped. The ventral 

 arm plates are subpentagonal, slightly in contact with one another. 

 The arm spines are variable in length ; the ratio of their length 

 to the corresponding arm joint in different parts of an arm may 

 be shown approximately as- follows : — 



