26 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 8 



largest. A number of the plates bear a short, heavy, tapering spinelet. 

 There are from 15 to 20 spinelets irregularly placed on the disk, but they 

 are even more numerous along the sides and margin of the disk. Radial 

 shields long and narrow, about 3 times as long as broad, separated by a 

 series of scales proximally, distal half fully in contact. Surface of radial 

 shields finely granulate. Genital plates in contact with the distal margin 

 of the radial shields and visible from above. 



Upper arm plates triangular, twice as broad as long, an obtuse angle 

 proximally, sides slightly convex, distal margin variable according to the 

 number of pieces in the upper plate. Upper plates variable, sometimes in a 

 single piece but often 2 distinct lateral sections and from one to 6 median 

 pieces, usually one small triangular piece distally, 2 small median triangu- 

 lar pieces or often additional pieces proximally. The upper plates are in 

 contact basally, but distally they become separated by the side arm plates. 

 Side arm plates with a prominent spine ridge bearing 3 heavy, tapering, 

 bluntly tipped arm spines. Middle spine longest, about as long as an arm 

 segment. Spines on the first arm plate very short and stubby; they gradu- 

 ally increase in length to the 6th arm segment, from whence they are more 

 or less uniform distally. 



Oral shields diamond shaped, slightly wider than long, with an acute 

 proximal angle. Adoral plates twice as broad as long, meeting within, 

 widest distally. Jaws long and narrow. Three oral papillae on a side, 

 outermost rectangular, longer than wide, with a serrate cutting margin ; 

 apical blocklike, well separated, longer than broad, cutting edges concave; 

 median heavy, triangular, about as long as wide. Four broad, flat teeth, 

 lowermost shortest, uppermost longest. No tooth papillae. 



Interbrachial spaces below covered with thick, overlapping, crowded 

 scales, a few bearing short, hea\y, sharp spinelets, irregularly distributed. 

 Genital slits bordered by a series of scales. First under arm plate small, 

 longer than wide, with an acutely convex distal margin. Second and suc- 

 ceeding plates pentagonal, wider than long, with an obtuse proximal angle 

 and straight lateral and distal margins. Plates barely in contact basally, 

 separated distally by the large, coarsely granulated side arm plates. Two 

 long, narrow tentacle scales attached on the distal side of the tentacle 

 pore. 



Color. — Dried specimens had dark cream-colored disks with darker 

 radial shields. Arms pinkish buff with irregular maroon bands and mark- 

 ings. Interbrachial areas below and mouth parts grayish white, under 

 arms pinkish buff with no banding. 



