Genera and Species of Brisingide. 419 
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; first 3 to 5 pairs of adambulacral 
plates united in each interradius, and above 
them the marginal plates are similarly 
united; asyzygy (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 semicoronata, Perrier .......... Odinia, Perrier. 
a’, A single circle of rather small papule near 
margin of disk, 2 papulz corresponding to 
each ray; rays, as in Brisinga, without 
papule. 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 figs, 8and 4), Geno- 
type, Brisinga mimica, Fisher .......... Brisingenes, Fisher. 
a*, No papule 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 pedicellariz 
arranged in transverse bands.* Geéno- 
type, Gymnobrisinga sarsti, Studer .... Gymmnobrisinga, Studer. 
6°, Abactinal skeleton present on disk, and on 
proximal portion of rays at least. 
e', 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 regular in- 
tervals all along side of ray; mouth- 
plates expanded fan-wise toward 
actinostome, nearly closing entrance 
1o 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; 
syzyay (?); related to Odinia, Geno- 
type, Brisingaster robillardi, de Loriol. Brisingaster, de Loriol. 
* Hymenodiscus, Perrier, belongs under this section. It is founded 
upon a very immature specimen, possibly a young Brisinga. 
28* 
