REPORT ON THE ASTEROIDEA. 
1. Form pentagonal, sides distinctly recti- 
lineal. Marginal plates ordinarily 
few in number , 
2. Form more or less pentagonal. Ex- 
tremities of the rays dilated or 
rounded. Marginal plates few in 
number . 
i. Marginal plates with fuleriea 
8. All plates covered with membrane, and bearing ay 
single, isolated, prominent, obtuse spinelets or elon- 
gate tubercles. No papule (?). No pedicellaria 
y. Actinal intermediate and infero-marginal plates spinu- 
late, and with small prominent spinelets inter- 
spersed. Abactinal plates granulose 
4. Supero-marginal plates united throughout the length of the ray. 
Abactinal plates confined entirely to the disk. Abactinal 
plates margined by peculiar valve-like plates. Abactinal 
plates naked . : 
b. Abactinal area with paxilliform plates. 
a. Paxille usually stellate and spinose. Mouth-plates with a pro- 
minent keel, developed aborally into a hyaline spiniform 
prolongation. Tegumentary covering of the whole test more 
or less spiniform or papilliform. With odd interradial 
marginal plates ; F ; : : : 
b. Paxilla tabulate, bearing granules or papille usually prismatic 
in form. Mouth-plates not keeled or prominent. No odd 
interradial marginal plates. 
a, Paxille confined to the disk-area. Rays long. Supero- 
marginal plates uniting in the median radial line, or 
separated only by a single series of quadrate plates. 
1, Adambulacral armature arranged in longitu- 
dinal series. Infero-marginal plates devoid 
of prominent tegumentary spinelets. With 
entrenched pedicellaria . 
. Adambulacral armature paoradiate aa 
transverse. Infero-marginal plates spini- 
ferous and with small prominent spinelets. 
No pedicellarie 2 ; 0 
8. Paxille extending along the ray. Supero-marginal 
plates separated by several series of paxille. 
Small valvate pedicellariz only, and very few in 
number. 
i. Marginal plates large and conspicuous. Abac- 
tinal plates small and not developed into 
large cylindrical tabula. Pedicellaria pre- 
sent . . . . . . : 
ii. Marginal plates comparatively small. Abac- 
tinal plates very large, with enormous 
cylindrical tabula, bearing co-ordinated 
granules. No pedicellaria 
263 
Pentagonaster. 
Astrogonium. 
Calliaster, 
Chitonastar. 
Calliderma. 
Tconaster. 
Gnathaster. 
Nymphaster. 
Paragonaster. 
Mediastar. 
Neetria.’ 
