STARFISHES OF THE PHILIPPINE SEAS. 119 



mediate plates. R = T8 mm., r=18 mm., R=4.3 r; breadth of ray 

 at midiiiterbrachium, about '20 mm. 



DescHption. — The most striking- difference betAveen this species 

 and P. euryacfis hrevisp'mus is in the narrower rays, which, instead 

 of being rather broad near the tip and then quickly narrowing to 

 an attenuate extremity taper gradually from a narrower base. The 

 superomarginals are of the same width in the two species, and as 

 a consequence the paxillar area is much narrower in luzonicus, its 

 width at one-third R from center being one and two-thirds to slightly 

 less than twice the extreme width of a neighboring superomarginal, 

 and at two-thirds R, about as wide as the superomarginal. In 

 euryactis these members are respectively "2.5 or 2.75 and 1.75. 



The paxillae are compact and the transverse series on the rays are 

 interrupted along the median line. The paxillae are relatively a 

 little larger than in euryactis. An average large paxilla from base 

 of ray or interradius has 18 to 25 peripheral and about the same num- 

 ber of slightly shorter central spinelets, slender, terete bluntly 

 pointed. Pedicellariae are very variable in occurrence. In the type 

 they are lacking, or at least very scarce, but in an example from 

 station 5329 they are very numerous, occupy the center of the tabu- 

 lum and consist of 4 to 6 spiniform jaws a little shorter and stouter 

 than the other spinelets. Abactinal plates broadly ellipitical to 

 subcircular. 



Superomarginals, 39 or 10. The lateral lace is about half as high 

 as width of dorsal, and on the well-rounded margin between the two, 

 and near the distal edge of plate, are borne 1, 2, or 3 short, flattened, 

 sharp, appressed spines. The plate is covered with appressed, 

 pointed squamules, which become slender small spinelets around the 

 borders of the plate, and especially in the shallow transverse chan- 

 nels between the plates. Terminal plate shorter and more ovoid 

 than in euryactis. 



Inferomarginal plates with a lateral comb of about 5 spines very 

 similar to those of euryactis^ and along the distal margin of the 

 actinal surface, are proximally 3 or 1 appressed shorter spines, which 

 are reduced distally to 2 and finally to 1. The second lateral series 

 is variable but usually fairly well developed, with 3 to 5 spinules 

 lying parallel to and under the upper half of the primary series. 

 It extends typically farther along the ray than in euryactis. The 

 plates are covered with flat round-tipped squamules, becoming longer 

 at inner end of plate and resembling those of euryactis. 



The actinal intermediate plates, owing to the narrowness of the 

 ray, are very small beyond tlie proximal third or fourth, and al- 

 though they extend to the twentieth or twenty-first inferomarginal, 

 or a little over one-half the length of ray, they are practically rudi- 

 ments attached to the inner edge of the inferomarginals. The inter- 



