Genera and Species of Brisingidge. 119 



pores ; ray with regularly spaced, lateral, 



transverse combs of upward of seven con- 

 spicuous slender spines ; adambulacral 



plates higher than long, with a single 



prominent subambulacral spine, frequently 



truncate and more or less spatulate proxi- 



mally ; -tirst 3 to 5 pairs of adambulacral 



plates united in each iuterradius, and above 



them the marginal plates are similady 



united; a syzygy (non-muscular symphysis) 



between first and second adambulacral 



plates, and also sometimes a partial syzygy 



between the second and third and between 



the third and fourth plates. Genotype, 



Brisinga semicorcmata, Perrier Odinia, Perrier, 



U-. A single circle of rather small papulae near 



margin of disk, 2 papulte corresponding to 



each ray ; rays, as in Brisinga^ without 



papulae. First and second adambulacral 



plates united by a syzygy (non-muscular 



symphysis), and upper part of second and 



third ambulacral plates united by syzygy ; 



gonads numerous, in series ; first pair of 



adambulacral plates in each interbrachium 



closely united (as in tigs. 3 and 4). Geno- 

 type, Brisinga mimica, Fisher Brisingenes, Fisher. 



«\ No papulae present either on disk or on rays. 

 6'. No abactinal skeleton on rays, the dorsal 

 side of arm being composed of integu- 

 ment without plates but covered with 

 numerous, relatively large pedicellarise 

 arranged in transverse bands.* Geno- 

 type, Ggmnobrisinga sarsii, Studer .... Ggmnobrisinga, Studer. 

 b"^, Abactinal skeleton present on disk, and on 

 proximal portion of rays at least, 



c\ Disk-plates large, with a comparatively 

 few fairly large disk-spines, and a 

 vertical series of about four con- 

 spicuous lateral spines to each succes- 

 sive skeletal arch of the rays, these 

 lateral combs occurring at reguhxr in- 

 tervals all along side of ray ; mouth- 

 plates expanded fan-wise toward 

 actinostome, nearly closing entrance 

 to ambulacral furrow ; subambulacral 

 spine with a modified truncate tip; 

 first pair of adambulacral plates of 

 each interbrachial angle united, but 

 the united pair of conspicuous first 

 marginal plates is interpolated from 

 above between their distal ends ; 

 syzygy (?) : related to Oclinia. Geno- 

 type, ^/7'sm</«s^er roAi//ar£?/,de Loriol. Brisingastev, de Loriol. 



* Hymenodiscus, Perrier, belongs under this section. It is founded 

 upon a very immature specimen, possibly a young BrisiiH/n. 



■2a* 



