On Fish-remains from the neighbourhood of Ludlow. 387 



fishes discovered by Mr. Salvvey in the Old Red Sandstone of Acton 

 Beauchamp, and others by Mr. Lightbody in the upper bone-beds 

 .near Ludlow. From the first-named locality the author described 

 a portion of a cephalic carapace, indicating a large and new species 

 of Cephalaspis (C. Salweyi). Another new species of Cephalaspis 

 (C. Miirchisoni) was founded on two sjiecimens obtained by Mr. 

 Lightbody in a bed below the ])aper-mill on the river Teme at Lud- 

 low ; and a third new species (C. ornatus) was described from spe- 

 cimens from dark micaceous shales in the Hereford Railway Cutting 

 at Ludlow. The same shales have afforded two specimens of a very 

 small Cephalaspid of great interest. These are of the size of a four- 

 penny piece, and have a general resemblance to Cephalaspis, except 

 in the peculiarity of having liehind the cephalic shield, and united to 

 its posterior margin by a distinctly marked suture, a broad plate 

 divided into lateral halves by a prolongation of the occipital crest. 

 The author, having stated his reasons for regarding these specimens 

 as adult and not embryonic individuals, gave this new Cephalaspid 

 form the generic title Auchenaspis (on account of its nuchal plate), 

 and described it under the specific name of .^4. Salteri. In conclusion, 

 some other ichthyic remains, referable to Plectrodus and Onchus, 

 were enumerated as having been collected by Mr. Lightbody in the 

 railway-cutting and in the River-bed near Ludlow. 



2. "Note on the relative position of the Strata containing the 

 Ichthyolites described by Sir P. Egerton." By Sir R. L Murchison, 

 V.P.G.S. 



The section of the railway-cutting north of Ludlow exhibits an 

 upcast mass of upper Ludlow rock a few feet thick and surmounted 

 by micaceous sandstone and red marl. It is distinct from, and 

 younger than the well-known Ludlow bone-bed, which is overlaid 

 in order by the grey-coloured Downton Castle sandstone. Though 

 higher in the series, still this band at the railway-cutting contains 

 some characteristic fossils of the lower bone-bed, such as the Plec- 

 trodus mirabilis }, Onchus Murchisoni }, and Lingula cornea. At the 

 same time it contains forms unknown in the lower beds, viz. Cepha- 

 laspis ornatus, Auchenaspis Salteri, an Onchus or Byssacanthus, Ptery- 

 gotus anglicus, and Eurypterus pygmaus. 



The section obtained on the right bank of the Teme, south of 

 Ludlow (between Ludford and the paper-mill), indicates that the 

 Ludlow bone-bed, dipping gently to the S.E., is covered by grey strata 

 representing the Downton Castle stone, which pass under brownish, 

 micaceous, thin-bedded sandstones, and these, to the east of the corn- 

 mill, are succeeded by red marl with cornstones. The fossiliferous 

 band exposed at the railway, though probably included in this section, 

 is not seen on account of denudation and superficial gravel ; but 

 another and still higher fossiliferous micaceous band, discovered on 

 the river-bank by Mr. liightbody, afforded the Cephalaspis Murchisoni 

 described by Sir P. Egerton, together with Plectrodus, Onchus Mur- 

 chisoni, and Lingula cornea. These tilestone-beds are succeeded by 

 the red marls, sandstones, and cornstones with Cephalaspis Lyellii, 

 Pleraspis Lloydii, &c. From the mingling of peculiar cephalaspid 

 forms with the Lingula cornea and Upper Silurian ichthyolites io 



2 D 2 



