EOCKS OP BOHEMIA. 607 



of Colonies, viz. the characteristic fauna of one great group (the 

 Silurian) existing in another locality in an earlier one (the Cam- 

 brian). We know of no such phenomena in any locality whatever, 

 or in any epoch. Why should these colonies occur only in Bohemia 

 (for the phenomena described as colonies in other countries have 

 been all proved to have a different origin)? and why do we not meet 

 with similar phenomena in other parts of the Palaeozoic rocks, or in 

 the Mesozoic or Cainozoic epochs ? 



In describing the characters of E e 1, and comparing this band 

 with its British equivalents, we found that it could, as in Britain, 

 be divided into three zones, characterized by particular Graptolites. 

 The lowest zone, characterized by the genera Diplograptus, Climaco- 

 graptus, and Bastrites, I shall speak of as the '^ Biplograptus-ZGne ;" 

 the middle, characterized by Monograptus priodon, M, vomerinus, 

 and Betiolites Geinitzianus, as the "Pr?oc?on-zone;" the upper, with 

 abundance of Monograptus colonus, as the " Golonus-zone." Now 

 not only are these different zones observable in e 1, but also in the 

 colonies ; and although they are not always all three present, still, 

 when more than one occurs in the same colony, they always occur 

 in the same stratigraphical order as that observable in e 1 ; whilst 

 if we take the whole series of colonies as bands occurring at different 

 horizons in d 5, no such order is observable. This is shown in the 

 following figure (fig. 5, p. 608). In this diagram, which contains only 

 colonies that I have examined, Colonic Haidinger and that at Hod- 

 kovicek (on the same horizon as Colonic Krejci) are on the S. side 

 of the basin ; whilst Colonic D'Archiac and that on the road to 

 Yohrada are on the N. side. The relative positions are, however, 

 proved by a black band containing abundance of Trinudeus Gold- 

 fussi, together with PJiacops (Dalm.) solitaria, &c., which is very 

 constant in d 5 in this part of the basin, and occurs at some distance 

 above Colonic Krejci, assuming the theory of colonies to be true, 

 whilst it is in contact with Colonic D'Archiac. The colony at 

 Lahovska, which I have not seen, is stated by Barrande (Def. des 

 Col. iv. p. 58) to be situated apparently between Colonies Krejci and 

 Haidinger. It contains Monograptus colonus. 



We can hardly conceive such a repetition of the different zones, 

 each in their proper order, in examining one colony, but in no order 

 at all taking the colonies as a whole, and yet the species never be- 

 coming intermixed. Further, the lowest zone of E e 1 was before 

 spoken of as being capable of division into subzones, characterized 

 by particular species of Graptolites. This is also the case with the 

 Diplograptus-zone in the colonies. Thus the lowest subzone in 

 two colonies which I have examined consists of the peculiar 

 " wafer " shales, crowded with Glimacograptus and Bastrites pere- 

 grinus, already described as characteristic of the lowest subzone of 

 the Diplograptus-zone of the main mass in E 1. Again, in the only 

 colony which has yielded Monograptus turriculatus this species was 

 found in a subzone of the Diplograptus-zone, very little below the 

 base of the Priodon-zone ; this, as before stated, is its position in 

 the main mass of e 1. 



