STARFISHES OF THE PHILIPPINE SEAS. 507 



there are only 6 or 7 easily recognized costae (only about 5 being 

 conspicuous), confined to the proximal fourth or less of the ray, and 

 the proximal ridges are very indistinct, with a few scattered spines 

 in the median region and none on the sides ; there is a short suboral 

 spine, and the marginal oral spinelets are shorter. 



ODINIA MAGISTER Fisher. 



Plate 143, figs. 1, 2; plate 144, fig. 2; plate 151, fig. 4; plate 152, figs. 3, 3a (see 

 also plate 152, fig. 2, Odinia pact flea). 

 Odinia magistcr Fisher, 1917?;, p. 93. 



Diagnosis. — Differing from O. pacifica Fisher in having a per- 

 fectly smooth integument on the genital region, in having more nu- 

 merous, stouter and shorter spines (6 or 7) on the largest lateral fans 

 beyond the genital region, and in having a differently formed artic- 

 ulating surface to the first pair of ambulacral plates of the ray. Disk 

 and number of rays unknown. Ray 350 to 360 mm. ; breadth at base, 

 measured at fifth adambulacral plate (the first one which is not 

 joined to its vis-^i-vis of the adjacent ray) 10 mm. Size very large; 

 genital region occupying about one-fourth total length of ray, and 

 crossed by about 10 costae, the first 4 or 5 being very irregular and 

 hard to distinguish; lateral spines 5 to 7, 4 and 3 distally; only 1 

 actinal adambulacral spine, proximally flattened and grooved at 

 tip; pedicellariae all small; none on the integument of genital 

 regioi?; no integumentary prickles or spinelets. 



Description. — Ray greatly swollen for about a fourth of its length 

 by the gonads, the highest portion being 25 mm., about 25 mm. from 

 the base. The breadth at this point is 17 to 20 mm. The swollen 

 region tapers from this place into the distal two-thirds of the arm, 

 which is not enlarged. The skin of the genital region is smooth and 

 entirely devoid of prickles or minute spinelets of any sort, and there 

 are no thickly and evenly distributed pedicellariae, such as charac- 

 terize O. paciflca. This skin hides the reticulated skeleton of the 

 basal portion of the ray. For the first 40 mm. of the ray the costal 

 bands of plates are evident superficially only in the mid-dorsal 

 region, where each spaced ridge bears 1 to 3 stout acicular spines 

 about 7 mm. long, incased in a sacculus of pedicellariae. The inter- 

 vals between the ridges are 5 to 10 mm., differing with the distension 

 of the integument. If a portion of the body wall is treated with 

 caustic potash and dried the plates are seen to be very irregular in 

 shape and diverse in size. The costal plates are elongated, with 

 often 1 or 2 lateral lobes, while the plates which bear the spines are 

 stellate, with 5 or 6 broad, more or less unequal, lobes. The inter- 

 costal plates are thin, flat, and overlapping. In the very irregular 

 spaces between them 1 to 5 long vermiform, pointed papulae emerge. 



