STAEFISHES OF THE PHILIPPINE SEAS. 47 



a". An odd interradial marginal in both series ; a double column of actinal inter- 

 mediate plates replacing the interradial fascicle, and meeting the odd 

 marginal Prionaster Verrill. 



Genus GONIOPECTEN Perrier. 



Ooniopecten Perkier, 1881, p. 24. Type, O. demonstrans Perrier. 



GONIOPECTEN ASIATICUS Fisher. 



Plate 4, fig. 1 : plate 5, fig. 2; plate 7, figs. 3, 3rt-c; plate 8, figs. 1, la. 

 Goniopecten asiaticns Fisher, 1913«, p. 601. 



Diagnosis. — Differing from G. demonstrans Perrier in having a 

 complete series of spines on both supero- and inferomarginal plates, 

 and open cribriform organs between the proximal marginals. R=135 

 mm., r=27 mm., R==5 r; breadth of ray at base, 31 mm. Disk mod- 

 erate; rays long, stout, with vertical sides. Marginal plates mas- 

 sive, with fasciolar grooves containing cribriform organs, those prox- 

 imally being open as in Porcellanasteridae. Paxillae large, crowded, 

 with upward of 60 short, subequal spinelets on rather high tabula. 

 Adambulacral plates with 6 to 10 furrow spines, the adoral con- 

 spicuously enlarged on the proximal plates; also with 1 or 2 promi- 

 nent subambulacral spines distall}^ 5 to 8 proximally. 



Description. — The abactinal paxillae are close-set, frequently in 

 contact, flat-topped, and rather large. The largest are on the proxi- 

 mal radial areas, decreasing in size toward center of disk and along 

 rays, and from the radial line toward margin of area. On outer 

 fifth of ray the superomarginals are in contact medially. The paxil- 

 lae are arranged in not at all regular, oblique, series extending from 

 the narrow median radial area, where they are not in regular order, 

 to marginal plates, about 7 of these ill-defined rows corresponding 

 to 2 superomarginal plates at base of ray. The bases of the median 

 radial paxillae are broadly elliptical; those of the dorsolateral areas 

 are subcircular or poorly defined hexagons and pentagons. Neither 

 sort are very regular, and the plates are separated usually by a slight 

 interspace. The plates have a high shaft or tabulum, slightly nar- 

 rowed at the summit and often variously compressed or with 3 to 5 

 unequal sides, rather than a circular cross-section. The spinelets are 

 very much shorter than the tabulum and commonly stand upright, 

 forming a compact elliptical, or three to five-sided group of 40 to 

 60 (on the larger paxillae) . The spinelets are cylindrical, membrane- 

 invested, and the tip is rounded or often knobbed with membrane, 

 while the peripheral series has an inconspicuous web at the base. 

 When the spinelets radiate apart the paxilla is roundish. Far along 

 the ray there are 10 to 15 spinelets on the dorsolateral paxillae, and 

 upward of 40 on the median radial. 



Papulae absent from median radial line; elsewhere usually in 

 sixes about each plate. 



