ROCKS OP BOHEMIA. 603 



chison (Siluria, p. 377), and Bellerophon hilobatus is common to tlie 

 two. Grraptolites also occur in this band in Bohemia, although not 

 abundantly. Oraptolitlius avus, recorded by Krejci, seems to in- 

 clude fragments of more than one compound form ; the same author 

 also records a Didymograptus (I). Suessi). The Graptolites occur 

 in deep-water deposits at several horizons (e.g. D d 3, d 5, E el), 

 but are absent in beds formed in a shallower sea. 



D d 2 was evidently deposited in shallow water, and cannot 

 therefore be strictly compared with any British deposit. The 

 fauna presents resemblances to that of the Lower Bala rocks of Britain. 



D d 3 is another deep-water deposit, resembling many of the 

 Bala shales of Britain. Many of the fossils of d 1 y have returned 

 with the recurrence of deep-sea conditions. Some obscure Graptolites 

 at Yinice are apparently referable to Climacograptus. The most 

 abundant Trilobite is Trinudeus ornatus {=T. concentricus). 



D d 4 seems to have been for the most part deposited in shallow 

 water. Its fauna is very similar to that of the Middle Bala. In it 

 occurs abundance of Ocdymene, Gheirurus, Phacops, lUcenus, 

 Trinudeus (T. ornatus = T. concentricus, abundant here also), and 

 various Cystideans. The limestone and calcareous shales described 

 as occurring at Yraz point to deeper water, and present a resem- 

 blance to the Bala limestoue. They contain Gheirurus claviger, 

 Phacops (Dahnannites) socialis, var. proceva, lUcenus Salteri, Orthis 

 elegantula and other species, Strophomena, Holopea, &c. 



D d 5 may partly represent tipper Bala beds. This and D d 4 

 being mostly shallow-water deposits, we cannot expect to find any 

 strong resemblance to English formations ; d 5 does, however, 

 contain one zone of fine black shales, very similar to some of the 

 English Bala shales, and apparently deposited in deep water. It 

 rarely contains Graptolites. 



III. The Silurian rocks, as before stated, rest with a slight uncon- 

 formity upon the Cambrian series, and their basement beds are 

 sometimes of a gritty and conglomeratic nature. These basement 

 beds have as yet yielded no fossils, so that in Bohemia there is no 

 sign of a shallow-water May-Hill fawna. The beds of E, especially 

 of its lower division, are more strictly comparable with their British 

 equivalents than any other beds of the basin ; for they contain a 

 series of graptolitic faunas which, as lately shown by Mr. Lapworth, 

 in his most instructive paper on the Moff'at series (Q. J. G. S. 

 vol. xxxiv. p. 333 &c.), are exceedingly limited in a vertical 

 direction, but widely spread horizontally. 



The band e 1 contains three graptolitic faunas. The beds con- 

 taining them have been already described, and their fossils will be 

 considered at length, as the recognition of these three faunas is of 

 the utmost importance in considering M. Barrande's theory of 

 colonies. The lowest of the three was described as consisting of 

 fine black prismatic mudstones with interstratified green bands, and 

 these are exactly similar to the beds of the Birkhill Shales of Britain. 

 The fauna presents a still more striking resemblance. I have found 

 in them the following species : — 



