1913.] Clark, Echinoderms from Lower California. 201 



In the presence of only three series of actinal intermediate plates and in 

 its small median, radial plates, this species resembles Myxoderma, a sub- 

 genus suggested by Fisher. But the spinelets are not sacculate, not at 

 least to any notable degree, and there is only one papula to each area. 

 This combination of characters taken with the long flat spines along the 

 sides of the ray, actinally, serve to distinguish the species from any Zoroaster 

 hitherto described. It is difficult to decide whether the flattened appear- 

 ance of the rays is natural or artificial, but it is quite marked in both 

 specimens. Possibly these specimens are not adult and spinelets and 

 pedicellarite would both be more abundant with age. 



Station 5675. Southwest of San Cristobal Bay, west coast of Lower 

 California, 284 fms. Bottom Temp., 44.6. 



Two specimens. 



Heliaster kubiniji. 



Xantus, 1860. Proc. Philadelphia Acad. Nat. Sci., p. 568. 



All but one of these specimens is adult. Ten have 23 rays, three have 

 22 and one has 24. The largest has R -- 70 mm. 

 Pichilingue Bay, east coast of Lower California. 

 Ricason Island, Conception Bay, east coast of Lower California. 

 Fourteen specimens. 



Pedicellaster hyperoncus l sp. nov. 

 Plate XLIV, Figs. 3 and 4. 



Rays 5. R = 68 mm.; r == 7 mm. R = 9| r. Breadth of ray at base. 7 mm. 

 Breadth of ray, 10 mm. from base, 11 mm. Breadth of ray, 10 mm. from tip, 7 mm. 



Disk small, flat; rays rather long, decidedly constricted at base and correspond- 

 ingly swollen just beyond, not attenuate, bluntly pointed; median radial ridge 

 not prominent ; spines not numerous, rather small; pedicellarise abundant. Papular 

 areas on rays with 2-5 papulae. Adambulacral plates numerous with only one spine 

 but often with a large pedicellaria also. Tube-feet in two well-defined rows. 



Abactinal skeleton fairly heavy on disk, but very open and rather delicate on rays. 

 None of the primary plates are easily recognizable on disk. All of the disk plates 

 carry spines, none of which are conspicuous, but the one near center of plate is the 

 largest. On the rays, the plates usually carry only a single spine each. All the 

 abactinal plates carry numerous small forcipiform pedicellariae ; they occur actinally 

 as far as the inferomarginal plates, each of which carries one or two. 



1 virtpoyxos = overgrown, of excessive size. 



