on the Genus Paleeacis. 209 
septal strie, a feature which will be entered on more fully 
in our own remarks on this genus. 
Another excellent paper on Paleacis was that by Dr. Kunth, 
“ Korallen des schlesischen Kohlenkalkes ”’*. 
Dr. Kunth agreed with Von Seebach as to the identity of 
Paleacis and Sphenopoterium ; but he believed the determina- 
tion of the systematic position to be a matter of some difficulty, 
although he ultimately agrees with Edwards and Von Seebach 
as to its being a member of the Madreporide, but differs from 
them as to the subfamily to which the genus should be re- 
ferred. He very justly observes that, from the figures given 
by various authors, there appears to be no proper coenenchyma 
in Paleacis, and would place it in the subfamily Eupsammine, 
having its nearest ally in Astroides ; indeed, he adds, its re- 
semblance to A. calycularts, Pallas, is very great, only the 
latter has a columella and more strongly developed septa. 
By far the most important point brought forward by Kunth 
was the determination of mural pores, visible when the surface 
was worn, with an irregular direction and disposition, and 
corresponding to canals which traverse in every direction the 
substance of the skeleton, giving to it a spongy appearance, 
and placing the various cups in connexion with one another f. 
Dr. Kunth gave a detailed description and figure of Ptycho- 
chartocyathus lacus, Ludw., which he considered to be a 
species of Palwacis, from its general structure, external granu- 
lated surface, basal attachment, and the cup-like openings with 
circular mouths, and separated from one another by shallow 
depressions, &c. The determination of species in Paleacis, 
Kunth considers to be a difficult matter, from the few striking 
characters presented by the specimens. The external form is 
so open to modification from age, position, and condition of 
life, that little reliance can be placed on this. He confirmed 
von Seebach’s union of the two species, P. cunetformis, Kd. & 
H., and P. cuneata, M. & W., and further expressed his 
opinion that von Seebach’s own species, P. cymba and P. 
umbonata, and P. obtusa, M. & W., may, in reality, represent 
only one species §, an opinion in which we quite concur. 
Prof. L. G. de Koninck has devoted much attention to this 
genus; for in his ‘Nouvelles Recherches sur les Animaux 
Fossiles du Terrain Carbonifére de la Belgique ’||, a lengthened 
description is given, accompanied by copious notes on its 
history and structure. The observations of Kunth on the 
* Zeit, deutsch. geol. Gesellsch. xxi. pp. 1838-220. 
+ Loe. cit. p. 187. { Loe. cit. pp. 185, 186. 
§ Op. cit. p. 188. 
|| 1** partie, pp. 154-161 (Bruxelles, 1872, 4to). 
