56 Mr. C. Lapworth on the Geological 



Barrande's first list of his species of the colonies is as 

 follows : — 



Monograptus priodon, Brown. Monograptus Rcemeri, Barr.* 

 bobemicus, Barr. colonus, Barr. 



a very probable association, but one which (as we shall sub- 

 sequently show) would in Britain be at once set down as 

 probably existent at the Wenlock period. A fauna distinctly 

 of far older date is given in the extended Catalogue of the 

 Colonial Graptolites printed in the fourth part of the ' De- 

 fense des Colonies.' From the Colonie d' Archiac, Barrande f 

 enumerates the following species (exclusive of undescribed 

 forms) : — 



Rastrites peregririus, Barr. Monograptus priodon, Bronn. 



Diplograptus folium, His. Nilssoni, Barr. 



Monograptus spinigerus, Nich. Becki, Barr. 



Hisingeri, Carr. colonus, Barr. 



nuntius, Barr. bohemicns, Barr. 



As a whole this is a group of forms that might be looked for 

 at the very base of the Gala or Tarannon group. There are, 

 however, two forms, M. colonus, Barr., and M. bohemicus, Barr., 

 which are not met with in Britain or Scandinavia until we 

 reach the Wenlock shale. They are, however, represented in 

 the much earlier Gala rocks by the allied forms M. galaensis, 

 Lapw., and M. concinnus, Lapw. 



In the Colonie Haidinger the following forms are pre- 

 sent : — 



Rastrites peregrinus, Barr. Monograptus colonus, Barr. 



Diplograptus palmeus, Barr. Nilssoni, Barr. 



Monograptus Becki, Barr. proteus, Barr. 



bohemicus, Barr. spiralis, Grin. 



an assemblage clearly of the same general geological date as 

 that in the Colonie d' Archiac. 



From the Colonie Krefci the only forms enumerated by 

 Barrande are 



Monograptus bobemicus, Barr. Monograptus priodon, Bronn. 

 colonus, Ban-. Rcenieri, Barr. 



These are Barrande's original Colonial forms, and, as already 

 hinted, suggest a Wenlock age for this special colony. 



The shaly zone Eel, at the base of the series of strata 

 containing the Third Fauna of Barrande, affords precisely the 

 same general group of Graptolites as the typical Colonies 



* Barrande, Grapt. de Boheme, p. 18. 



t Barrande, Defense des Colonies, iv. p. 126. 



