EXPLANATION OF THE PLATES. ol 
PLATE XVII. 
FOSSILS OF THE WENLOCK ROCKS. 
ZOOPHYTA.—_ANTHOZOA. 
Fic. 1.—a, 6, ec. HELIOLITES INTERSTINCTUS, Linneus, sp. 
Porites pyriformis, Sil. Syst., p. 686; Sil., 4th ed., pl. xxxix., fig. 2. 
a. Hemispheerical group of corallites in Wenlock limestone, Much Wenlock, 
Shropshire. From Brit. Foss, Corals, Pal. Soc., pl. lvii., fig. 5. 
b. Portion of the surface enlarged from same plate, fig. 5 b. 
c. Original. Vertical section; Wenlock limestone, Dormington Wood, 
Gloucestershire. Mus. G. §. I. 
Caravoc to Luprow Rocks.—Sil., 4th ed., p. 510. This widely-distri- 
buted and very abundant Silurian coral occurs in Lower Silurian rocks of 
Caradoc age at Coniston, Westmoreland; south of Llangollen, North 
Wales ; and Portraine, Co. Dublin. In Wenlock limestone at Wenlock, 
Dudley, Aymestry, Ledbury, &c. In Wenlock rocks at Ballintemple and 
Doonquin, Kerry; Kilbride, Galway ; and Uggool, Mayo. 
Norer.—lIt is very probable that H. megastoma M‘Coy, sp., Pal. Foss., 
p. 16, Z he fig. 4, will be found to be merely a variety of this species. 
—W. H. B. 
Fic. 2.—a, b, c. FAvostrres cotHianpicus, Lanarck. 
Silurian System, p. 682; Sil., 4th ed., pl. xl., figs. 3,4. Brit. Foss. Corals, 
. 256. 
a. §iae view of a vertical series of corallites; from Sil. Syst., pl. xvi. dis, 
fig. 3. 
db. Impression of the surfaces ofa group of corallites. From Brit. Foss. Corals, 
pl. lx., fig. 1 a ; near Tortworth. 
e. Enlarged portion ; from Sil., 4th ed., Foss. 18, fig. 3, p. 119. 
Carapoc to LupLow Rocxks.—Sil., 4th ed., p.510. This equally abundant 
and widely-distributed species is found in many Lower and Upper Silurian 
localities. Caradoc strata S. of Llangollen. M. G. S., vol. iti., p. 260; 
Llandovery ; several localities in Wales and Shropshire. In Wenlock 
rocks at Aymestry, Ledbury, Wenlock, Radnor, Dudley, and Tortworth ; 
and from equivalent rocks in Ireland at Innishvickillane, South Blasket 
Island, Kerry; Bolingbroke, Tipperary; and Kilbride, Galway. 
Fic. 3 a-d. HALYSITES CATENULARIUS, Linnaeus, sp. 
Catenipora escharoides, Sil. Syst., p. 685. H. catenularius, Sil., 4th ed., 
pl. xl., fig. 14. Brit, Foss. Corals, p. 270, 
