Ch. XXVI.] 



LOWER DEVONIAN. 



541 



fer," because they contain in abundance a fossil body of very curious 

 structure, Calceola sandalina (fig. 614), which has been usually con- 

 sidered a brachiopod, but which some naturalists have lately referred 

 to a coral. They suppose it to be an abnormal form of the order 

 Zoantharia rugosa (see fig. 563, p. 515), differing from all other 

 corals in being furnished with a strong operculum. 



Lower Devonian. 



Beneath the Middle Devonian limestones and schists already enu- 

 merated, a series of slaty beds and quartzose sandstones, the latter 

 constituting the "Older Rhenish Greywacke" of Rorner, and the 

 " Spirifer sandstone " of Sandberger, are exhibited between Coblentz 

 and Caub.* A portion of these rocks on the Rhine and in some of 

 the adjacent countries was regarded as " Upper Silurian " by Prof. 

 Sedgwick and Sir R. Murchison in 1839, but their true age has since 

 been determined. Their equivalents are found in England in the 

 sandstones and slates of 



the Foreland and Linton *%• 615 - 



in Devon (Nos. 4 and 5 

 of the table, p. 536), 

 and, according to Mr. Sal- 

 ter, in the sandstone of 

 Torquay in South Devon, 



where many of the char- Spirife?'mucronatus,E.&ll. Devonian of Pennsylvania, 



Fiff. 616. 



Homalonotus armatus, Burmeister. Lower 

 Devonian ; Daun, in the Eifel. 



Obs. The two rows of spines down the body 

 give an appearance of more distinct trilo- 

 bation than really occurs in this or most 

 other species of the genus. 



Fig. 61T. 



Pleurodiciyum problemaiicum, Goldfuss. 

 Lower Devonian ; of Plymouth and Tor- 

 quay ; Looe ; Forez, &c. ; also in Germany 

 at Dietz, Nassau, &c. ' 



Obs. Attached to a worm -like body (Serpula). 

 The specimen is a cast iu sandstone, the 

 thin expanded baso of the coral being re- 

 moved, and exposing the large polygonal 

 cells ; the walls of these cells are perforated, 

 and the casts of these perforations produce 

 the chain-like rows of dots between the 

 cells. 



* Murchison's Siluria, p. 368. 



