STARFISHES OF THE PHILIPPINE SEAS. 533 



actinostomial margin. These carry numerous slender- jawed pedi- 

 cellariae. 



Madreporic body prominent, flat-topped, with numerous, rather 

 coarse, interrupted, sinuous furrows. The articulation surface of 

 the ambulacral plates at junction of ray with disk is about as broad 

 as high, equally broad at top and bottom and with a prominent 

 median suture. 



Type.—C^i. No. 37025, U.S.N.M. 



Type-locality. — Station 5648, Buton Strait, Celebes, 559 fathoms, 

 green mud, bottom temperature 39.2° F. ; the type-specimen and 2 

 incomplete specimens. 



Disfjihufion. — China Sea, off southern Luzon, and Buton Strait, 

 Celebes, 525 to 559 fathoms. 



Specimens examined. — In addition to the types, rays without a 

 disk from station 5274, China Sea, vicinity of southern Luzon, 525 

 fathoms, gray mud and sand, bottom temperature 41.3° F. 



Remarks . — Brislnga gracilis Koehler, from the Bay of Bengal, 

 east of the Andaman Islands, resembles this species in having plates 

 between the costae and at the base of the ray before the costae com- 

 mence, but they bear spinelets. Koehler does not state that the plates 

 are close together nor unusual in number, as in the case of the present 

 species. However, in gracilis the costae begin at a distance from the 

 disk and the "plates which were invisible on the dorsal surface of 

 the disk become distinct on the rays; they are irregular, roundish, 

 and bear each a little conical spinelet, rough and pointed, broader at 

 the base and shorter than those on the disk." (Koehler, 1909, p. 

 115.) In typical Binsinga the spaces between the costae are either 

 free from plates or have embryonic spaced platelets which bear each 

 a minute spinelet or prickle, but which do not form an armor such 

 as exists, in a more perfected form, in Freyella. 



KEY TO THE INDO-PACIFIC SPECIES OF BRISINGA AND EUISINGA-LIKE GENERA. 



In the following more or less artificial key I have not been able to 

 assign the species described by Alcock and Wood-Mason to the newer 

 genera described by me. They have been listed as B rising a. 



c\ Intercostal integument of proximal part of ray thin, with or without rudi- 

 mentary spaced plates bearing a minute spinelet; proximal subambulacral 

 spines acicular, not broadened into a more or less truncate capitate tip. 

 6\ Intercostal membrane without integumentary prickles. 

 &. Plates of disk each with a group of several spinelets. 

 (Z\ Costae numerous — more than 30. 

 e\ Costae close together, very prominent, without intercostal bands of 

 pedicellariae ; rays 12 or 13 ; disk moderate, with rounded margin 

 and spinelets in groups of 2 to G resembling pseudopaxillae ; adam- 



1-1-7 '/ 

 biilacral armature , ^ or ^ . ^-\-I Erisingn irachi/disca Fisher. 



13434— Bull. 100—19 35 



