32 Proceedings of the Biological Society of Washington. 



cellarife, and with relatively coarse spinelets, the costal region occupying 

 more than a third of the total length of ray but less than one-half; adam- 

 bulacral plates not crowded; armature with 1 aboral furrow spinelet, 1 

 adoral actinal spine, \}4 to 1% the length of the plate, and 1 prominent 

 actinal spine 3 times the length of plate. Rays slender, very long; 

 breadth of disk equals 4 to 4^ times width of ray at base. 



Type.— Cat. No. 37,020, U. S. N. M. 



Type-locality. — Station 5491, between Leyte and Mindanao, 736 fathoms, 

 green mud, coral, bottom temperature 52.3° Fahr. 



This species differs from B. andamanica in having more closely crowded 

 costse, with strongly, not feebly developed plates, in having a longer 

 costal region, in lacking well-developed bands of pedicellarise between the 

 costse and in having fewer (12 or 13, not 15), less deciduous rays. 

 B. gunnii differs in having more numerous rays, much thinner disk, 

 which has a downy appearance, only 20 to 30 ridges, especially promi- 

 nent laterally but obsolete abactinally, intercostal bands of pedicellarise, 

 a much shorter major subambulacral spine, and mouth plates composed 

 of 2 incompletely fused adambulacrals, leaving a " ligamentous symphysis 

 between." 



Brisinga mimica new species. 



Diagnosis. — Rays 16. Costse numerous (25 to 30), closely placed, 

 prominent, irregular, with relatively coarse spinelets, without intervening 

 bands of pedicellarise; costse confined to basal fifth of ray, beyond which 

 for an equal distance are about 15 very inconspicuous ridges composed of 

 small plates, but carrying a fairly heavy felting of pedicellarise ; disk large, 

 with isolated delicate spinelets not in groups; adambulacral plates proxi- 

 mally wider than long and crowded in appearance; armature typically 

 1 aboral furrow spinelet, 1 aboral actinal spinule and 1 longer adoral 

 actinal spine (equaling 2 plates in length), and 1 major spine about 3 

 plates in length. Rays slender, very long; R=:385 mm., r=19 mm. 



Type.— C&t. No. 37,021, U. S. N. M. 



Type-locality.— Station 5648, Buton Strait, Celebes (5° 35^ S. , 122° 20^ E. ) , 

 559 fathoms, green mud; bottom temperature 39.2° Fahr. 



B. insularum has 13 rays and disk spinelets in groups, intercostal ridges 

 of pedicellarite, only 13 to 17 costse, and longer lateral spines. B. benga- 

 lensis has 14 rays, a small disk, with the abactinal spinelets in tufts, 20 

 costse, occupying basal ninth of the ray, intercostal bands of pedicellarise 

 equally salient with the ribs. 



Brisinga moluccana new species. 



Diagnosis. — Rays 16. Costse 25, complete, prominent, well-spaced, 

 with 1 to 3 intercostal bands of pedicellarise; costal spinelets relatively 

 coarse; disk medium, with isolated papilliform, small, spinelets, and 

 minute pedicellarias ; adambulacral plates about as wide as long proxi- 

 mally ; armature typically : 1 true furrow spinelet at either end of plate 

 and equal to about % the length of plate ; aborad and actinad to the 



