34 Feather stonhmigVs Geological Report. 



The Caradoc beds* The beds of this division consist, in 

 the lower part, of thick-bedded red, purple, green, and white 

 freestones, conglomeritic quartzose grits, and sandy and gritty 

 limestones. Various undescribed species of trilobites, and 

 differing from those in the overlying beds ; numerous species 

 of the genus orthis, together with nucula and pentamerus, are 

 found here. The upper beds are thin-bedded impure shelly 

 limestone, and finely-laminated, slightly-micaceous, greenish 

 sandstone. The organic remains are pentamerus, leptaena, 

 pileopsis, and orthis, all of new species. There are also tere- 

 bratula ; and the tentaculites and crinoidea are abundant ; 

 corals rare. 



Wenlock limestone and shale. The lower beds are liver 

 and dark gray colored argillaceous shale, rarely micaceous, with 

 nodules of earthy limestone. The organic remains are as- 

 aphus caud, calymene Blumenbachii, lingula, orthis, cyrtia, 

 delthyris, orthocera, crinoidea ; most of them new species. 



The upper beds are that highly concretionary gray and 

 blue subcrystalline limestone, the equivalent of the well- 

 known Dudley limestone ; abounding with corals and crino- 

 idea, bellerophon, euomphalus, conularia, pentamerus, natica, 

 leptaena, spirifer, terebratula, producta, orthocera, asaphus, 

 calymene, and various species of trilobites. 



Ludlow rocks. The lower beds of this formation are sandy, 

 liver and dark colored shale and flags, with concretions of 



* Mr. Murchison, in conformity with the practice of attaching the names of 

 remakable localities to their rocks when first described, has here very happily 

 associated some of the most interesting traits of British Celtic history with his 

 geological labors. The rocks comprehended in his Silurian system were ob- 

 served by him in that part of the country which constituted the ancient king- 

 dom of the Silures, that Celtic nation which so bravely resisted the Romans 

 under the Emperors Claudius and Nero. Caer Caradoc, from whence the 

 Caradoc beds are named, is the name of a highly picturesque ridge in Shrop- 

 shire. Camden, the historian, supposes it to have been the locality where the 

 celebrated leader of the Silures, Caractacus, (Caradoc,) made his last stand 

 against the "Roman forces. 



