Genera and Species 0/ Brisingidas. 421 



slender, acicular ; the acces- 

 sory sulDambulacral spine, if 

 present, is on tbe adoral half 

 of the plate; adambulacral 

 armature is not dense and 

 crowded. Genotype, Bri- 

 singa endecacnemos, Asbj <^rn- 

 sen Brisinga, Asbjc^rnseu. 



g"^. Subambulacral spinesof proxi- 

 mal adambulacral plates with 

 modified, capitate, often trun- 

 cate tips ; second subambu- 

 lacral spine regularly present, 

 prominent, and near the ab- 

 oral end of plate ; adambu- 

 lacral plates short, with 

 crowded armature. Geno- 

 type, Brisinga panopla, 



Fisher Craterohrisinga, Fisher. 



f^. Gonads two to each ray (one 

 on each side) ; subambulacral 

 spines all delicate and acicular. 



g^. The iuterradial (first) pair of 

 adambulacral plates is joined 

 by the interradial faces, and 

 above them is a united pair 

 of first marginal plates — four 

 in all (figs. Sand 4). Geno- 

 type, Brisinga moluccann, 

 Fisher Astrostephane, Fisher.* 



g'^. The interradial (first) pair of 

 adambulacral plates is not 

 joined, but separate, the outer 

 end of the combined mouth- 

 plates being usually inter- 

 polated between the inner 

 ends of these adambulacral 

 plates ; first pair of marginal 

 plates is not closely united 

 by the interradial faces, but 

 only by the adoral ends, to 

 which also is closely united 

 the lower end of the inter- 

 radial platp, formiusr a rude 

 reversed Y, of which the 

 angle is the apex of the in- 

 terbi-achial angle and the 

 arms are the first marginal 

 plates (figs. 5 and 6) ; ad- 

 ambulacral plates slender, 



* Includes also Astrostephane acanthogenys (Fisher), from 172 fathoms 

 off Lingayau Gulf, Luzon. The type is from 265 fathoms between 

 Gillolo and Kayoa Islands, Molucca Islands. (Fisher, Proc. Biol. Soc. 

 Washington, vol. xxix. p. 33, Feb. 24, 1016.) 



