STAEFISHES OF THE PHILIPPINE SEAS. 509 



Remarks. — This large species differs from 0. pacliica in liaving 

 more numerous, stouter, and shorter spines on the largest lateral 

 fans. In facif,ca the spines are 4 to a comb, very slender, and the 

 longest equal 7.5 to 8 plates in length while in magister there are 



6 or 7 spines, G to 6.5 plates in length. In maghter the skin of the 

 genital region is perfectly smooth ; in facijica it is thickly peppered 

 with minute pedicellariae. The articulating surface of the first pair 

 of ambulacral ossicles (at base of ray) has, in magister.^ a nearly 

 elliptical contour, but in paciflca the upper end is much broader than 

 the lower (see pi. 152, figs. 2 and 3a). 



Odinia fenichra Fisher and 0. clarki Koehler have a furrow 

 spine : the former has spinelets on the integument between the proxi- 

 mal costal ridges, and scattered pedicellariae, while clarki has a long 

 genital region with numerous complete costae, bearing each a com- 

 plete series of robust conspicuous spines, and has only 4 spines in 

 the lateral fans beyond the genital region. 



In O. austini Koehler, which is of a delicate habit, like pem'cAra, 

 there are no furrow spinelets, but at the very base of the ray there 

 are abactinal spinelets scattered among the papulae, the well spaced 



7 or 8 costae are quite distinct, and there are only 3 or 4 lateral 

 spines beyond the costal region. 



Genus BRISINGA Asbjornsen. 



Brisinga Asbj0rnsen, Fauna Litt. Norvegiae, 1856, andet hefte, p. 95. 

 Type, B. endecacnemos Asbj0rnsen ; Fisher, 1917/, p. 421, figs. 1 and 2. 



Diagnosis. — Brisingidae without papulae ; with the abactinal skele- 

 ton of rays in the form of transverse independent arches separated by 

 intervals lacking plates (except sometimes microscopic plates carry- 

 ing minute prickles) ; with numerous gonads forming a series along 

 either side of each ray; with a syzygy or nonmuscular symphysis 

 between the first and second adambulacral plates, and between the 

 upper end of the second and third adambulacral plates ; with a united 

 pair of first adambulacral plates, and first marginal plates in each 

 interbrachial angle — 4 plates in all; Avith the subambulacral spines 

 of proximal plates acicular, unmodified; accessory subambulacral 

 spine, if present, on adoral half of plate. 



Remarks. — In B. trachydisca Fisher the distal ends of the first or 

 united pair of adambulacral plates of each interradius are wedged 

 apart by the united first marginal plates — or, rather, appear to be. 

 In Sars' admirable monograph of Brisinga coronata^ two figures of 

 B. endecacnemos (Sars, 1875, pi. 8, figs. 8 and 9) show that the first 

 adambulacral plates are not joined so closely as in Brlsingenes., As- 

 trostephane^ or Stegnohrisinga. But the structure of these inter- 

 radially situated adambulacrals and marginals is quite different 

 from that of the same plates of Brisingella^ as may be readily de- 



