70 
ASTEROIDEA. 
Ohs . — Starfisli are not known to occur either in the Carboniferous 
or Permo-Carboniferous rocks of Western Australia, or Queensland. 
Order — Encrinasteriae. 
Tamihj—l^ALJEASTEniBj'E. 
PAL.EASTER, Rail, 1852. 
(Pal. New York, ii. p. 217) 
Ohs . — The genus Balceaster ranges from the Upper Silurian to the 
Carboniferous, but its representation in rocks of the latter period is far more 
limited as regards species than in those of the former. The three species 
from the Permo-Carboniferous of New South Wales, now referred to 
BaUeasler, although possessing the general features of the genus, differ in 
an important particular from Hairs original types, P. matnlbui} and 
P. eucliaris? In both of these, and in other Silurian and Devonian forms, 
the adambulacral plates, bordering the ambulaeral avenues, are small and 
quadrangular, followed by large transverse marginal plates. In our Permo- 
Carboniferous species, on the contrary, the adambulacral plates (PI. XV, 
Pig. I) are transversely elongated, and occupy nearly the Avhole of the 
actinial surface on each side the avenues.^ The marginal plates, in contra- 
distinction to those of Hall’s Silurian species, are here smaller and suh- 
dorsal in position (PI. XIV, Pig. 2). The question now presents itself, of 
what value in a classificatory sense is this character ? Hall lays particular 
stress on the position of these plates on the actinial side of J?al (caster. He 
says^ it “ has two ranges of plates on each side of the ambulaeral groove ; 
marginal and adambulacral plates on the lower side, besides ambulaeral or 
poral plates. The upper or dorsal side has three or more ranges of plates.” 
In the case of our specimens, only one set of jiHtes, excepting those of the 
ambulaeral grooves, are, as before stated, absolutely actinial ; the marginal 
are strictly so, or, at the least, suh-dorsal. Under these circumstances, I 
' Twentieth Ann. Report N. York State Cab. Xat. Hist., 1867, p. 283, t. 9, f. 2. 
Loc. cit., p. 287, t. 9, f. 3, 3* *, 3“, anil 4. 
5 This feature is also visible in He Koninck’s figure, Foss. Pal. Nouv.-Galles du Sud, 1877, Ft. 3, 
t. 7, f. 6'. 
* Twentictli Ann. Report N. York State Cab. Nat. Hist., 1867, p. 283. 
