Ch. XXVI.] FOSSILS OF MIDDLE DEVONIAN. 539 



Fig. 60T. Tig. 60a 



Eeliolites porosa, Gol&f., sp. Pontes pyriformis, 



Lonsd. 

 a. Portion of the same, magnified. Middle Devo- 

 nian, Torquay ; Plymouth ; Eifel. 



Aulopora serpens, Goldf. 



(The young basal portion of a Syrin- 



gopora, Milne Edw. and Haime.) 



becomes a cluster of tubes connected by minute processes. In this 

 state it lias been supposed to be a distinct coral, and has been called 

 Syringopora. 



With the above are found many stone-lilies or crinoids, some of 

 them, such as Cuprcssocrinites, of forms generically distinct from those 

 of the Carboniferous Limestone. The mollusks also are no less char- 

 acteristic, among which the genus String 'ocephalus (fig. 609) may be 



StringocepTialus Burtini, Defr. (Teredratula porrecta, Sow.) Eifel; also South Devon. 

 a. Valves united. 0. Side view of same, 



c. Interior of larger valve, showing thick partition, and part of a large process which 

 projects from the other valve quite across the shell. 



mentioned as exclusively Devonian. Many other Brachiopod shells, 

 of the genus Spirifer, &c, abounded, and among them the Atrypa 

 reticularis, Linn. sp. (fig. 627, p. 554), which seems to have been a 

 cosmopolite species occurring in Devonian strata from America to 

 Asia Minor, and which, as we shall hereafter see (p. 554), lived also in 

 the Silurian seas. Among the peculiar lamellibranchiate bivalves com- 

 mon to the Plymouth Limestone of Devonshire and the Continent, we 

 find the Megalodon (fig. 610), together with many spiral univalves, 

 such as MurcJiisonia, Uuomphalus, and Macrocheilus ; and Pteropods 

 such as Conularia (fig. 611). The cephalopoda, such as Cyrtoceras, 

 Gyroceras, and others, are nearly all of genera distinct from those pre- 

 vailing in the Upper Devonian Limestone, or Clymenien-Kalk of the 

 Germans already mentioned (p. 537). Although but few species of 

 Trilobites occur, the characteristic Brontes fiabellifer (fig. 612) is far 

 fr^m rare, and all collectors arc familiar with its fan-like tail. The 



