210 Mr. R. Etheridge and Dr. H. A. Nicholson 
structure and position of the pores perforating the substance 
of Palceacis are confirmed. A point upon which Dr. Kunth 
appears to have had some doubt, the presence or absence of a 
columella, is also set at rest by De Koninck, who proved the 
entire absence of this structure. Milne-Edwards, in his de- 
scription of P. cunetiformis, mentions the presence of two large 
septa, which Prof. de Koninck does not appear to have met 
with in the specimens he had examined. He also agreed with 
Dr. Kunth that, contrary to the opinion of Haime, there is no 
independent ccenenchyma in Paleacis; and, in consequence, the 
enus was removed to the Hupsammine, after Kunth; but, 
unlike the latter, De Koninck would not place it near Astroides, 
but probably between Cenopsammia and Stereopsammia, the 
latter, like Palwacis, being devoid of a columella. 
Including in this genus the two forms mentioned in the 
first two paragraphs of this paper (Hydnopora? cyclostoma, 
Phill., and <Astreopora antiqua, M‘Coy), Prof. de Koninck 
would reduce the number of known species to four, viz. :— 
1. Paleacis cunetformis, J. Haime. 
= Sphenopoterium cuneatum, M. & W. 
2. Paleacis (Sphenopoterium) compressa, M. & W. 
3. Paleacis (Sphenopoterium) obtusa, M. & W. 
= Paleacis cymba, v. Seebach ; Paleacis umbonata, v. Seebach. 
4, Paleacis cyclostoma, Phillips. 
= Sphenopoterium enorme, M. & W.; Ptychochartocyathus laxus, Ludw. ; 
Astreopora antigua, M‘Coy. 
In 1873 one of the present writers (R. E., jun.) published 
a few remarks on the occurrence of this genus in Scotch Car- 
boniferous beds, in the ‘ Memoirs of the Geol. Survey of 
Scotland’ *. It was shown that specimens of Paleacis cyclo- 
stoma, Phill., from Mid-Lothian usually possessed from five to 
nine cups ; an entire absence of columella was remarked upon, 
and some other minor points were noticed fT. 
One of the latest notices of Paleacis, of which we have any 
knowledge, is a short account of the discovery of the typical 
species of the genus in Britain—P. cunetformis, J. Haime 
(=P. (Sph.) cuneata, M. & W.)—by Mr. Spencer G. Perce- 
* Explanation to sheet 23 (1-inch, Scotland), p. 96. 
+ In these remarks I published what I then believed to be a new 
variety of Paleacis compressa, M. & W., under the name of trregularis, 
I now find I was much mistaken in the affinities of the bodies so called, 
ae oe desirous of withdrawing the name from paleontological science.— 
