20 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 8 



scales, 10 of which bear stout, cylindrical, bluntly rounded papillae twice 

 as long as wide, 2 in each interradius. The marginal fence consists of 8 to 

 10 broad, flat papillae almost as wide as long, heavy and blunt. Radial 

 shields small, almost twice as long as broad, less than half the disk radius 

 in length. Their pointed ends proximally are separated by 2 or 3 disk 

 scales; distally they are in contact. 



Upper arm plates broadly oval with rounded lateral margins, fully 

 in contact with the distal margins overlapping the proximal margins of 

 the succeeding plates. Side arm plates narrow, separated from each other 

 by a naked membrane ; arm-spine ridge prominent, bearing 3 short, heav)^ 

 flattened, bluntly pointed arm spines, about twice as long as broad, equal 

 to the length of an arm segment. 



Oral shields diamond shaped, about as long as wide; distal margins 

 slightly concave. Adoral plates broader than long, margins almost paral- 

 lel, meeting fully within. Jaw plates long and narrow, meeting proxi- 

 mally to form a V. Three oval papillae on each side, distal 2 broad, block- 

 like, and rounded ; distalmost only slightly larger ; apical papillae block- 

 like, longer than broad, widely separated. No tooth papillae; teeth wide 

 with rounded cutting edges. 



Interbrachial spaces below covered with overlapping scales, more or 

 less uniform in appearance. Two long genital slits in each interradius. 

 First under arm plates rectangular, wider than long, with a notched prox- 

 imal margin. Second plate squarish with a concave distal margin; suc- 

 ceeding plates about as wide as long, with convex lateral margins ; distal 

 margins slightly wider than proximal, fully in contact with each other, 

 the outer one slightly larger. 



Color. — Dried specimen, disk almost white, a purplish tinge on the 

 primary plates. Upper arm plates irregularly marked, some plates white, 

 others almost black with variations of brown plates with dark markings, 

 white plates with brown and black markings and white plates with par- 

 allel lines; there is no definite banding arrangement. Arm spines tinged 

 with purple. Under side entirely white with a few dark bands on the 

 distal under arm plates. 



Type. — Holotype, AHF no. 11. 



Type locality. — Station 260-34, shore, Tangola Island, Tangola- 

 Tangola Bay, Mexico, March 1, 1934. 



Remarks. — This species is easily distinguished from all known mem- 

 bers of the genus by the 10 cylindrical papillae on the disk. Because of this 

 characteristic feature the name papillatus has been selected. 



