on the Genus Paleacis. 207 
“ne parait pas en différer”’ (¢. e. the two species). However, 
in their ‘Monograph of the British Carboniferous Corals ’*, 
all doubt on the subject appears to have left their minds; for 
they there consider the two as identical, under the one name 
Propora? cyclostoma. So far as we have been able to ascer~ 
tain, no further effort towards the elucidation of these fossils 
was made for some time; but in 1860 Milne-Edwards de- 
scribed, in the third volume of the ‘ Histoire Naturelle des 
Coralliaires’t, a genus established by Jules Haime shortly 
before his death, but never described by him, under the name 
of Paleacis, containing a single species, P. cunetformis}, from 
the Carboniferous rocks of Spergen Hill, Indiana. The genus 
is thus described: —‘ Polypary free but composite, rounded and 
very compressed at its base. Calices disposed, one at the 
summit, and the others in pairs upon the two lateral margins. 
Coenenchyma finely vermicular.”’ It is provisionally assigned 
to the Madreporide, subfamily Turbinarine. The chief points 
brought out in the specific description are the cuneiform 
nature of the corallum, the presence of from two to five calices, 
each occupied by thirty or forty fine unequal striz represent- 
ing the septa, two of which are both described and figured as 
being stronger than the others. 
About the same time Messrs. Meek and Worthen had under 
observation similar fossils, to which, in a paper entitled “ De- 
scriptions of new Carboniferous Fossils from Illinois and other 
Western States ’§, they applied the name of Sphenopoterium, 
and considered them to be corals allied to Cyathoseris, Kdw. 
& H.; they, however, remark that they differ in having the 
outer wall perforated, and in the absence of distinct septa, as 
well as in the peculiar wedge-like form of the base of the coral- 
lum, which is usually, if not always, free instead of being at- 
tached. In their generic description of Sphenopotertwm, Meek 
and Worthen state that the cells are large and inseparable, and 
increase by lateral and interstitial development ; there are no 
tabule, columella, or well-developed rays ; but the walls are 
merely marked by distinct strie, and pierced by numerous 
pores which appear to terminate in the porous substance of 
the corallum. ‘They describe four species—S. obtuswm (the 
type), S. compressum, S. enorme, and S. cuneatum. It stands 
to reason, from their remarks and comparison with Cyatho- 
serts, that they considered Sphenopoteriwm to be a member of 
the Madreporaria Aporosa, family Fungide. 
= 2162, i Bae. 
{ Loe. ct. pl. E. 1. f. 2. 
§ Proc. Acad. Nat. Sciences Philadelphia for 1860, pp. 447, 448. 
