NO. Z 



2 ziesenhenne: newophiurans 17 



the median row overlaps the adjoining rows. There are from 11 to 18 

 stout, cylindrical marginal papillae in each interradius. Radial shields 

 longer than wide, length equal to half the disk radius, in contact except 

 inner ends, where a small scale separates them. 



Upper arm plates transversely oval, proximal margin broadly convex, 

 distal margin straight overlapping the margin of the succeeding plate. 

 Side arm plates not meeting above or below. Spine ridge bears 3 some- 

 what flattened, bluntly pointed arm spines, about an arm segment in 

 length ; middle arm spine slightly the longest. 



Oral shields diamond shaped, about as long as wide, with rounded 

 angles. Adoral plates swollen, broader than long, meeting within. Jaws 

 small and triangular, a deep depression between them. Three oral papillae 

 on a side, outermost largest, somewhat triangular, about as broad as long; 

 median small, flat, peglike, longer than broad; apical blocklike, heavy, 

 slightly longer than broad. Four broad teeth, uppermost longest. 



Interbrachial spaces below covered with minute overlapping scales. 

 The scales are so fine and crowded that they can only be taken for gran- 

 ules under low magnification; only under high magnification can the 

 scales be distinctly seen. Genital slits long, extending from the oral shield 

 to the disk margin; the edge bears a row of overlapping scales, larger 

 than the under disk scales. First under arm plates small, triangular, angle 

 within, distal margin straight. Second and succeeding plates pentagonal, 

 about as broad as long basally, and becoming longer than broad distally. 

 Lateral, proximal lateral, and distal margins slightly concave. The basal 

 7 or 8 plates have a notable raised median ridge. Tentacle scales 2, a 

 small, narrow, oval outer scale attached to the side arm plate and a rela- 

 tively huge spearhead-shaped inner scale, almost twice as long as broad, 

 attached to the under arm plate. The smaller scale is not present on the 

 distal third of the arm. The large scale is not present on the last 15 arm 

 segments, nor is it conspicuous on newly regenerated segments. 



Color. — Dried from alcohol, disk and arms light gray, with irregular 

 brownish drab arm bands on distal third of arms. Marginal papillae and 

 arm spines pale gray. Under disk surface light gray, mouth parts and 

 under arm lighter. The paratype, dried from alcohol, is dark brownish 

 drab; under disk surface, marginal papillae, and arm spines gray. The 

 median ridge of the basal under arm plates is also pale gray. 

 Types. — Holotype, AHF no. 19; one paratype. 



Type locality. — Holotype and paratype from Station 964-39, 2-8 

 fms., Tenacatita Bay, Mexico, May 8, 1939. 



