508 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



Beyond the first 40 mm. of the ray the costae become well defined 

 and increasmgl}'^ more prominent, especially on the sides, and bear 

 about 10 spines, spaced all the w&y across the arm, and longest lat- 

 erall}^ (10 mm.). Beyond the 80 mm. mark they become more and 

 more localized laterally into fans of sacculated spines borne on a 

 prominent transverse ridge, while the median portion of the ray is 

 devoid both of spines and plates. Proximally there are 6 or 7 spines 

 to a comb (the second and third from the lowest usually the longest, 

 about 12 mm.), then 5 for a considerable distance, then 4, and finally 

 3 at the end of the ray. (See pi. 143, fig. 2.) As soon as the spines 

 are segregated on lateral combs, pedicellariae in circular cushions 

 appear on the radial area and between the combs, and these pads or 

 flaps sometimes coalesce into incomplete transverse bands. The 

 spines themselves are invested with a thick sacculus, covered with 

 small pedicellariae. 



The papulae extend about 110 mm. from base of ray (one-third the 

 total length), and the lateral papulae are often very much swollen 

 at the base, as if distended by products of excretion. 



The adambulacral plates are higher than long and bear only 1 

 large erect spine, which, proximally, is usually flattened and sub- 

 truncate at the tip. The terminal portion is not much widened, but 

 there is usually a very evident longitudinal furrow (sometimes 2). 

 The spine then has a couple of incipient truncate or sharp extremi- 

 ties. Beyond the basal third of the ray the extremity of the spine 

 is tapered and either sharp or truncate, and often retains the groove 

 and the 2 more or less well-defined tips. On the outer side of the 

 spine is a thick felting of pedicellariae on a flange of tissue which 

 extends as a flap or pennant beyond the tip of the spine for half or 

 fhree-quarters its length. The combs of lateral spines are opposite 

 about every third adambulacral plate ; there are thus 2 plates inter- 

 polated between the plates which have the lateral spines opposite 

 them. 



The proximal half of the " genital region " is packed witli the 

 gonads which consist of long, slender, mostly dichotomously branched 

 tubules. These converge and open to the exterior 19 mm, from the 

 base of the ray and 12 mm. above the actinal surface of the adambu- 

 lacral plates. The distal half of the inflated region is filled with 

 the lobulated tubules of the hepatic coeca, which extend nearly half 

 the length of ray. The lobes seem to be solid and are attached to a 

 long axial canal which is scarcely evident above the testes. The 

 lobules when crushed give out numerous oil globules. 



Type.— Cat No. 37026, U.S.N.M. 



TT/pe-Jocality. —Station 5258, off southern Panay (lat. 10° 27' 45'' 

 N. ; long. 122° 12' 30" E.) : marked intermediate haul in list of dredg- 

 ing stations. 



