STARFISHES OF THE PHILIPPINE SEAS. 521 



BRISINGENES ANCHISTA, new species. 



Plate 146 ; plate 153. figs. 3, Sa-d ; plate 154, fig. 4. 



Diagnosis. — Closely resembling B. mimica, but differing in having 

 14 rays, smaller pedicellariae, of which the proximal serrate portion 

 of each blade has more numerous teeth, and is of different form ; in 

 having more numerous and more regular prominent costae, longer 

 costal region, longer oral spines at mouth of furrow, longer mouth 

 plates, and decidedly larger articular surface to the ambulacral plates, 

 where ray is detached from disk. Adambulacral armature typically 



-— . Breadth of disk=4^ times width of ray at base; actino- 



stome=3 times same; height of disk=breadth of ray at base. R= 

 360+mm., r=19 mm. (tip of ray missing). Rays, 14. 



Desciiption. — Disk covered with fine spinelets, 1 to a plate, spaced 

 about their own length (0.5 mm.) apart and decreasing very slightly 

 in length toward the center of disk. Many of the spinelets have a 

 small pedicellaria attached to them, distinguished from those of S. 

 placoderma and B. mimica by difference in form and smaller size. 

 The margin of disk is rounded and at the base of each ray, on this 

 rounded border, are a couple of prominent papulae. 



Rays long, distall}^ slender, swollen beyond the base into a de- 

 pressed genital region. The difference in the costal region between 

 mimica and anchista is not great, but easily discernible, especially if 

 the rays are placed side by side. In anchista there are about 40 

 jorominent costae which occupy the proximal fourth of the ray, and 

 in addition there are about 10 or 12 very slender ridges beyond these. 

 The costae are straighter; that is, less sinuous, as a rule, than in 

 mim,ica, and the inconspicuous distal costae are fewer and occupy 

 less space. There is little, if any, difference in the structure of the 

 ridges themselves. In a few of the proximal intercostal spaces are 

 single rudimentary bands of pedicellariae. Usually the intercostal 

 spaces are without such bands. There is a subtriangular marginal 

 plate opposite every other adambulacral; and opposite each inter- 

 vening plate is a costal ridge which has no enlarged lateral plate and 

 usually does not touch the adambulacral. The first lateral spine is 

 opposite about the fifteenth adambulacral plate and only 1 mm. long. 

 At the end of the region of prominent costae they are about 10 mm. 

 long, or the length of 4 consecutive plates; opposite the last rudi- 

 mentary rib they are 16 mm. long or ^ adambulacral plates in length. 

 The}' have a heavy membranous investment. 



Proximal adambulacral plates wider than long with an armature 

 very similar — almost identical — to that of B. mimica. The typical 



formula is j The principal variations are occasionally an 



/i+2 + 1\ 

 additional aboral subambulacral spinule ( ^ )t or the aboral 



