88 BRITISH SILURIAN BRACHIOPODA. 
given by Schlotheim, in 1820, is the Chapel of Pancratius, near Prague. The figure 
represents an undeterminable fragment of a striated Spirifer, from which no certain identi- 
fication can be arrived at; but I have no doubt that the Baron, at p. 47 of his ‘ Ueber 
Delthyris, oder Spirifer und Orthis,’ 1837, imagines our Silurian shell from ‘ Dudley 
Castle” to be the Zerebratulites striatissimus of Schlotheim. At page 38 of the same 
work he considers Delthyris cyrtena, Dal., from Gothland, to be a synonym of Spzrifer 
pinguis, Sowerby, although no two species could be more dissimilar; and, in addition, 
they belong to two distinct periods. 
One thing, however, may be inferred, namely, that Von Buch considered Sp. cyrtena, 
Dal., and Sp. radiatus, Sow., to be two distinct species, although he adopted for both of 
them erroneous denominations. 
The external sculpture, when well preserved, is extremely beautiful, and consists of 
radiating ribs (five in the width of a line in the middle of an average-sized specimen), not 
always quite regular in their respective widths, but usually leaving an interspace between 
each two of about the width of one of the ribs, and at times towards the margin 
there are smaller ribs interpolated; these ribs are regularly crossed by equidistant, 
concentric, projecting ridges, which give to the shell surface a beautifully imbricated 
appearance. 
Position and Locality. Spirifera plicatella, vay. radiata, is a very common fossil in the 
Wenlock limestone at Dudley. 
Phillips and Salter, at p. 292, vol. ii, of the ‘Memoirs of the Geological Survey of 
Great Britain,’ name the following localities :—Brock Hill Section (Lower Ludlow) ; 
Hast of Ledbury (Wenlock limestone); under Worcester Beacon (Woolhope limestone), 
and near Winning’s Farm (Caradoc! sandstone), all in Malvern district; Hole Farm, 
Lower Ludlow, and Callow Farm, Abberley district; North of Canwood, Wenlock 
limestone; East of Canwood, Dormington Wood; Lindels’ Green; Wootton Farm, 
Checkley Common, in the Woolhope district ; and at west of Rock Farm, Wenlock 
hmestone; May Hill: Huntley Hill, in the May Hill district. Mr. Salter mentions 
its presence in the Lower Llandovery rocks of the Quaker’s Burial ground, near 
Welchpool, the only locality known in rocks below the Upper Silurian. 
In Sweden Herr Lindstrém found the shell at Wisby, Likershamn, Mid.-Gotland ; 
Djupvik (Eksta), Lilla och Stora Carlsé ; Petesvik (Habblingbo), Endre, Hejdeby, Lergraf, 
Boge, Faro. It occurs also in Ehstland, and in several other districts. Prof. Halk 
informs us that it is abundant in the upper limestone of the Clinton group at Lockport, 
Lewiston, and other places in the Niagara country, is less abundant in the same 
position at Rochester and other eastern localities, and that it is found also in the Niagara 
shale. 
1 Upper Caradoe, i.e. May Hill sandstone, or Upper Llandovery rock. 
