WENLOCK SERIES. 99 



characteristic Corals. It thins out entirely in Radnorshire, and is 

 very feebly represented in Brecon, Caermarthen, and Pembroke ; 

 for its place is only marked in the cliifs of Marloes Bay, west of 

 Milford Haven, by some fossils and a small quantity of impure 

 limestone in grey and sandy shale. ^ 



The Wenlock Limestone is well developed at Malvern (280 feet), 

 Woolhope, May Hill (220 feet), Tortworth, and Usk. (See Figs. 

 4, 12, 13, and 14.) Among the most noted localities, however, 

 are the Castle Hill and Wren's Nest at Dudley, where the 

 limestone (Dudley Limestone) has been largely quarried, and is 

 locally known as the "White lime." Here it forms two bands of 

 concretionary and flaggy limestone, the upper twenty to thirty feet 

 thick, and the lower thirty-five to forty feet, separated by about 

 ninety feet of shale. The Wenlock Limestone is also to be seen 

 at Walsall. The occurrence of Wenlock Beds at Pen-y-lan east of 

 Cardiff was made known by the Rev. Norman Glass ; their total 

 thickness, including Wenlock Shale, at Pen-y-lan and Rhymney, is 

 estimated at 580 feet by Prof. Sollas.- 



The Wenlock Limestone is a noted repository for fossils. 

 Among these are Sponges, Stromatopora striatella, Ischadites, etc. ; 

 and Graptolites, Dictyo7iema retifonnis, etc. More abundant are the 

 Corals, Omphyma turbinata, Heliolites intcrstincta, Halysitcs catcnu- 

 larius (the " Chain Coral "), Favosi'tcs Gothlandica, Cyathophylliim 

 angustiim. The Echinoderms include Ac/mocrimis pulc/ier, Cyatho- 

 crinus pyriformis, Crotalocrinus rugosus, Taxocrmus tesseracojitadadyliis, 

 Pseiidocrinitcs quadrifasciafus, Periechocrinus moniliformis, etc. The 

 Crustacea include the Cirripede Turrilepas Wrightianus, and the 

 Trilobites, Acidaspis crenatiis, Encrimirus punctatus and E. variolaris 

 (known as the "Strawberry-headed" Trilobites), Calymene Bliimcn- 

 hachii (the " Dudley Locust"), Lichas anglicus, Phacops Dowimtgice, 

 P. caudatiis, Proctus Stokesii, Sphcerexochus minis, and Homalo7iotus 

 delphinoce phaliis . Pterygotus problematicus has also been found. 



The Polyzoa include many species of Fencstella, besides other 

 forms.^ The Brachiopods include Strophomena eiiglypha, S. rhom- 

 boidalis, Pentamerus galeatus, Spirifcra elevata, S. plicatdla, Orthis 

 elegant Ilia, Atiypa reticularis, Athyris compressa. Men's tella circe, Retzia 

 Barrandei, Rhynchonella borealis, R. Stricklandi, R. Wilsoni, and 

 Lingula Lewisii. The spiral appendages of many Brachiopoda 

 {Spirifera, Athyris, Atrypa, etc) have been worked out by the Rev. 

 Norman Glass. ^ 



The Lamellibranchs include Aviciila mira, A. ampliata, Grammy sia 

 cingiilata, Orthonota amygdalina, Pterinea lineata, etc. Fossil pearls 

 have been somewhat doubtfully identified. The Gasteropods in- 

 clude Euomphahis fiinatus, E. rugosus, HolopeUa obsoleta, Murchisonia 

 Lloydii. The Pteropods include Conularia Soiverbyi. The Hetero- 

 pods include Bellerophon dilatatus, and B. Wenlockensis. The 



^ Murchison, Siluria, edit. 5, p. 115. See also Prestwich, T. G. S. (2), v. 413. 



^ Geologist, iv. 168 ; Q. J. xxxv. 475. 



^ See G. W. Shrubsole, Q. J. xxxvi. 241. 



* See T. Davidson, Silurian Brachiopoda (Palreontograph. Soc). 



