78 
JOURNAL OF THE GEOLOGICAL SOCIETY OF DUBLIN. 
The one identified with Rissoa Altenburgensis has the whorls more drawn out 
than in R. Gibsoni; and the latter has apparently more whorls than the 
former. In some respects they resemble my Loxonema fasciata and L. 
Geinitziana , both of which, however, are more elongated. Possibly the shell 
I have identified with Brown’s Rissoa Gibsoni is the same as the Trochus 
pusillus of Geinitz. I observed similar shells in Mr. M‘Adam’s collection of 
Cultra magnesian limestone fossils. “ Some obscure univalves”'are noticed in 
Dr. Griffith’s list. Rissoa Gibsoni occurs near Manchester, and R. Alten¬ 
burgensis in Germany. 
13. Cythere ? inornata, M'Coy _PI. i., fig. 13; Monograph, pi. xviii., fig. 9. 
Only two distinct specimens of an Entomostracan have been found at Tully- 
connel; they are not exactly alike in outline, but sufficiently so to be re¬ 
garded, for the present, as belonging to one species, which is somewhat 
between the carboniferous Cythere inornata of M‘Coy, and the Permian C. 
Geinitziana of Jones. As a Permian fossil, the present species occurs on the 
coast of Durham. 
There are thus thirteen species occurring in the Tuilyconnel 
Magnesian Limestone, all of which are true Permian forms. Fur¬ 
thermore, the deposit is chemically and lithologically the same as 
much of the Magnesian Limestone in the county of Durham, and in 
Germany. The same may be said of the Cultra “ fossiliferous dolo¬ 
mite.” It necessarily follows, then, that the existence of the Per¬ 
mian system in Ireland, is placed beyond all doubt. 
The question next arises as to which of the Permian subdivisions 
the Tuilyconnel and Cultra dolomite belongs. 
In my Monograph* I published the following Comparative Table 
of the constituent members of the German and the North of England 
Permian System:— 
MEMBERS OF THE PERMIAN SYSTEM IN 
GERMANY. 
1. Stinkstein. 
2. Rauchwacke. 
3. Dolomit, or Zechstein Dolomit. 
4. Zechstein. 
5. Mergel-schiefer. 
6. Todte-liegende. 
MEMBERS OF THE PERMIAN SYSTEM IN 
THE NORTH OF ENGLAND. 
1. Crystalline and non-crystalline lime¬ 
stone. f 
2. Brecciated and pseudo-brecciated lime¬ 
stone.! 
3. Fossiliferous limestone. 
4. Compact limestone. 
5. Marl slate. 
6. Inferior or Lower New Red Sandstone. 
* Introduction, p. xvii. 
f There occur in Yorkshire and the adjacent counties beds of marl and gypsum 
which may belong to No. 1, or they may prove a still higher member. 
X In the second or brecciated member I have only found fossils which appear to 
have been washed out of the third or “ fossiliferous limestone” member. 
