EXPLANATION OF THE PLATES, 31 
PLATE XI. 
FOSSILS OF THE CARADOC OR BALA ROCKS. 
MOLLUSCA.—POLYZOA. 
Fie. 1.—a, 6, c. FENESTELLA ASSIMILIS, Lonsdale, sp. 
Gorgonia, Sil. Syst., p. 680. Fenestella, Siluria, 4th ed., pl. xli., fig. 27. 
a. Original. Showing fan-like form. 
b. Original. Enlarged portion with cells. 
e. Original. Enlarged portion of opposite surface, marked with irregular 
striations. All from grey limestone, Chair of Kildare, Co. Kildare. Mus. 
Geol. Surv. of Ireland. 
Carapoc and WENLOCK Rocks.—Sil., fourth edition, p. 523. Frequent in 
the Caradoc-Bala limestone of the Chair of Kildare ; it has also been col- 
lected by the Geological Survey from sandy shales of Caradoc age at Car- 
riganeagh and Frankfort, Co. Wexford, and is not uncommon in grey slates 
of the same formation at Munmahoge, between Waterford and Tramore, 
as well as in rocks of similar character on shore at Tramore Bay and at 
Newtown Head, Waterford Harbour. Mus. G.S. I. In Siluria, fourth 
edition, p. 216, it is figured (Fossils 50) as ‘a common Wenlock species.” 
It certainly is most characteristic of the Caradoc formation in Ireland. 
Nore.—In the Catalogue of British Fossils, by Professor Morris, second 
edition, p. 55, this species is said to occur in the county of Tyrone (I pre- 
sume on the authority of Colonel Portlock) ; my examination of the spe- 
cimens in the Portlock collection, Mus. Geol. Surv. of Ireland, leads me, 
however, to the belief, that he was mistaken in this supposed identification ; 
and that the specimens alluded to are closely allied, if not identical, with 
Callograptus elegans or Salteri of the Quebec group, described by Professor 
Hall in Decade 2, pl. xix., of the Geological Survey of Canada. 
Fic. 2.—a, b. Pritopicrya acuta, Hail, sp. 
Strictopora acuta, Paleontology of New York, vol. i., p. 74, pl. xxvi., fig. 3. 
Ptilodictya, Sil., fourth edition, pp. 188, 523. 
a. Original. Showing the dichotomous character of the branches. 
b. Original. Enlarged portion, showing alternating rows of cells, as in the 
recent Eschara, in grey limestone, Chair of Kildare. Mus. Geol. Surv. 
Ireland. 
Carapoc.—Sil., fourth edition, p. 523. Localities in Denbighshire, at Glyn 
Ceirog, S. of Llangollen (M‘Coy), in Montgomeryshire, at Llechweddwyd ; 
and Llanfyllin, Mem. Geol. Surv., vol. iii., p. 266. Frequent in the grey 
limestone of the Chair of Kildare; it is also plentiful in dark grey limestone 
at Portraine, Co. Dublin. 
F 
