10 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 8 



swollen, pentagonal, about as wide as long, with proximal margins 

 slightly concave, and lateral and distal margins convex; plates barely in 

 contact. Side arm plates narrow, bearing 3 blunt arm spines, the upper 

 one rectangular, very large, not twice as broad as long, resembling a 

 supplementary upper arm plate. Under and median spines of equal size, 

 short, flat, rounded, and longer than broad. Side arm plates meeting above 

 but not below. 



Oral shields, except the madreporite, rectangular, almost 3 times as 

 broad as long, distal margin only slightly convex. Adoral plates rectangu- 

 lar, meeting fully within, separated distally by a smaller triangular plate. 

 Jaws prominent, almost twice as long as wide. Three or 4 oral papillae 

 on each side and a triangular-shaped papilla on the apex of the jaw. Outer 

 papillae longest, broader than long; median peg shaped, blunt, forming a 

 straight line with the margins of the outer and apical papillae. Five 

 bluntly pointed teeth. 



Interbrachial spaces below covered with elongated, irregular disk 

 plates, 2 or 3 elongated plates bordering the base of the arms. Two small, 

 oval genital slits in each interradius in contact with the oral shield. First 

 under arm plate trapezoidal, about as wide as long, with a broad, slightly 

 convex distal margin. Succeeding plates rectangular with concave proxi- 

 mal and side margins and a slightly broader distal margin. The distal 

 portion of the plate overlaps the proximal margin of the succeeding plate. 

 One flat, rounded tentacle scale, about Y^ the length of the under arm 

 plate, attached to the side arm plate. 



Color. — Dried specimen, disk white centrally with a brownish tinge 

 on the margins. An irregular oval brown ring at the base of each arm 

 and one radiating out from the center of the disk to the interbrachial 

 area. Each of the larger disk plates bears a brown marking. The upper 

 arms bear a brown median stripe the width of the upper arm plate, 

 including the portions of the side arm plates that come within that width. 

 Bordering the brown median band is a white band, lateral to which is a 

 narrow brown line that disappears distally. The remainder of the side 

 arm plates and the median and lower arm spines are pink. The broad 

 upper arm spine is half white and half brown. The arms are uniformly 

 white at the tips, and the under arm plates are white; tentacle scales 

 white with a tinge of pink now and then. In life the disk was pale, its 

 sides really coral red and the lower surface quite red ; no distinct marks 

 on the disk; a deep yellow stripe (longitudinal) on upper surface of the 

 arm. 



