ASTEBOIDEA OF >'ORTH PACIFIC AND ADJACENT WATEBtJ — FISHER. MS 



Madroporic body ])roniinent, tubercular, situatfd midway bptwern center of 

 disk and interbracliial an<rlp, tlioic being small spinelets scattered on the surface. 

 Striations coarse, irrejjularly radiating. 



Color in life unknowTi; in alcohol whitish. 



AnaUrmical notes. — The plates are rather delicate and slexider, as would be 

 expected in a species of this genus living at such a depth. The best idea will he 

 gained from the figure. The papuL-c are single, and when viewed from the inner 

 surface of the integument are seen to be arranged in regular oblique transverse 

 series extending between the well-defined median radial series of plates and the 

 superomarginals. Externally the regularity is not very evident. 



Type.— Cat. No. 21931, U.S.X.M. 



Type-hcaliti/. — Albatross station 29.3(i, oil" San Diego, California, in .So9 fathoms, 

 on mud. 



Distribution. — Kno\^^l from tiio vicinity of type-locality oidy. 



Specimens examined. — From tyjie-locality, four; from station 2935, near type- 

 locality, 124 fathoms, fine gray sand, one specimen; locality unknown, one specimen. 



Remarks. — This s]3ecies is characterized by the presence of several spinelets 

 on the furrow face of the adambulacrals and by the small pseudopaxilhe covered 

 with numerous very minute spinelets; by the large single papula) regularly arranged 

 in oblique transverse rows, and by the small mouth plates and numerous adarabu- 

 lacral spinelets. It stands near to //. clarli. and to IJ. pauperrima Fisher of the 

 Hawaiian Islands. 



HENRICIA CLARKI Fisher. 



PI. 78, figs. 2, 3; pi. Ill, fig. 5; pi. 112, fig. 3. 

 Henricia clarki Fisher, Zool. Anz., vol. 35, March 29, 1910, p. 573. 



Diagnosis. — Rays long, very slender, and flexible, tapering from a narrow 

 base to an attenuate, blunt extremity; rays subcylindrical ; abactinal surface 

 depressed; Luterbrachial angles abrupt, about 90°, not rounded; disk very small; 

 plates delicate, forming a sinuous meshwork inclosing smaller, lower, secondary 

 plates (also more or less joineil in a close mesh) between which emerge single jiapula*; 

 adarabulacral plates wnth tliirty-five to forty spinelets on proximal part of ray, and 

 in the furrow two spinelets, except on the proximal six or eight plates, where there 

 are three to five in a vertical series. 



Description. — K = 54 mm.; r=7 mm.; R=7.7 r. Breadth of ray at base, 

 7 to 9 mm. Abactinal surface \vith an open meshwork of narrow small primary 

 plates, bearing contiguous roundish or elongate groups of about a dozen very small, 

 slender, and sharp spinelets which are not so long as the height of the ridg?s bearing 

 them. These primary plates form sinuous ridges inclosing fairly large, very irregular 

 spaces or meshes wliicli are filled by lower, smaller plates bearing single spinelets 

 or groups of two to six. These secondary plates in turn fonn a close meshwork 

 filling the larger primary meshes, but the summit or top of the secondary j)latcs is 

 sunken below tlie level of the primary ridges and the secondary spinelets are also 

 smaller and fewer in a group. This mesh witliiu a me.sh is very characteristic of 

 this species. In the intervals between secondary jilates single pajiuhv protrude. 



