210 SILUEIA. [Chap. IX. j 
fossils only. Rh. nucula, Sow., PI. XXII. f. 1, occurs with it at Tortworth and I 
May Hill. Another species, which cannot be distinguished from Rh. obtusiplicata ; 
of Hall, is found in the conglomerates on the west flank of the Worcester Beacon, 
Fossils (49). Some Llandovery Brachiopods. 
1 
1. Rhynchonella ? 
(like Eh. serrata, 
M'Coy). 2. Meris- 
tella angustifrons, 
M'Coy. 3. Orthis 
reversa, Salter. (All 
occur in the South 
of Scotland and the 
West of Ireland.) 
Malvern. Rh. serrata (?), M'Coy, Foss. 49, f. 1, a beautiful shell, with Rh. sex- 
costata, M'Coy, are found in Galway, the former also in Ayrshire. Retzia 
cuneata, Dalm., and Rhynchonella borealis, Schlot., are met with in the South 
of Scotland, with Rh. Wilsoni. This last-named fossil is thenceforward per- 
sistent throughout all the deposits to the Upper Ludlow inclusive. Atrypa (?) 
Grayii, Dav., Foss. 58. f. 3, and Meristella (?) didyma, Dalm., formerly regarded 
as Rhynchonellae, and characteristic Wenlock forms, are found in the upper 
beds, near Llandovery. 
The genus Atrypa is very abundant. A. marginalis, PI. LX. f. 2, is one of 
the common fossils of the formation. A. reticularis, PL IX. f. 1, and Foss. 15. 
f. 5, p. 90, appears to have commenced with the Llandovery period, and ranges 
upwards throughout all the overlying Silurian groups. On the other hand, A. 
hemisphserica, PI. IX. f. 3, is confined to the Upper Llandovery beds. This 
species swarms at Tortworth, Presteign, and Abberley, but is rare in Wales. 
Spirifer elevatus, Dalm., and Sp. exporrectus, Wahl., are found at Tortworth 
and May Hill (see Plates IX. & XXL). 
The well-known Lower Silurian Orthides, 0. calligramma, Dalm. (not flabellu- 
lum), and 0. elegantula, Dalm. PI. IX. f. 19 & 21, are somewhat frequent in the 
Llandovery rocks, and are also occasionally accompanied by 0. Actoniae, Sow., 
and O. insularis, Pander. Other species peculiar to these rocks are 0. reversa, 
Salter* Foss. 49. f. 3, and O. lata, Sow., PL IX. f. 23, whilst 0. biloba, Linn., 
and O. elegantula, Dalm., which are Upper Silurian species, are also known in 
both divisions of this formation. 
Of the genus Strophomena, the widely spread S. depressa, Dalm., which ranges 
from the Llandeilo to the Wenlock rocks, and S. antiquata, Sow., are common 
in the lower division ; S. bipartita, Salt. (S. alternata, Conrad), of Caradoc age, 
and S. euglypha, Dalm., of the Wenlock deposits, are more rare. In the upper 
beds, S. compressa, PL IX. f. 16, with S. pecten, Foss. 59. f. 3, and an un- 
described species, S. arenacea, Salter, MS., are frequent types. 
Leptaena transversalis, Dalm., and L. sericea, Sow., PL IX. f. 18, both well- 
known Lower Silurian fossils, with a small species, L. scissa, Salter, MS., are 
found in both of the Llandovery divisions, the first-named being the most com- 
mon fossil. 
Of Lingulae there are a few species : L. crumena, Phillips, Foss. 13. f. 5, p. 68, 
and L. parallela, PhilL, are common at Malvern ; and there is a species, yet 
unnamed, in the Lower Llandovery rocks. Discina (Orbicula, Sil. Syst.) is 
* M'Coy and Griffith's Synopsis of the Silurian Fossils of Ireland, Appendix, pi. 5. f. 2. 
