ANNIVERSARY ADDRESS OF THE PRESIDENT. Ixxi 



He then arranges all tlie species in a tabular form, showing not 

 only their vertical range in the different Tertiary stages in which 

 they occur, but also their horizontal development, viz. the different 

 Upper Ohgocene deposits in which they have hitherto been found. 

 This Hst shows that the Ahnegraben near Cassel has alone afforded 

 88 species, the greater part of which are only found in few localities. 

 Very few species have a wide distribution. With regard to the 

 vertical distribution, 67 species have been found only in the Upper 

 Oligocene, to which they seem peculiarly to belong ; 47 species de- 

 scend into the Mic'^l^^ Oligocene or Septaria Clay, and of these 5 

 reach the Miocene, 3 the Pliocene, and 1 species is still living. Alto- 

 gether the Upper Oligocene has 42 species in common with the 

 Miocene, 5 of which extend into the Pliocene and 10 are still living. 



*' Taking all these facts into consideration," observes Prof. Eeuss, 

 " we come to this conclusion, that the Eoraminiferous fauna of the 

 Upper Oligocene beds is very peculiar, and easily recognized under 

 all circumstances. The marks of distinction are partly common, 

 partly special : the former rest on the remarkable preponderance of 

 various PolymorpliinidecB and Cristellaridece, and on the abundance 

 of the otherwise scarce Flahellinoe ; the latter on the numerous 

 species peculiar to the Cassel beds, amongst which the above-men- 

 tioned 17 species are remarkable, partly for the great abundance of 

 individuals, and partly for their distribution over almost all the 

 Upper Oligocene localities." 



The author then gives a description of all the observed species, 

 with their situation, history, and localities, and adds five well-exe- 

 cuted plates of figured illustrations. 



2. Antliozoa. — Only seven species have hitherto been found which 

 can safely be referred to the Cassel beds ; others may perhaps be 

 found by other authors, but the characteristic evidence is still incom- 

 plete. Of these 7 species, 3 belong to the Caryophyllidece, 3 to 

 the Turhinolice, and 1, viz. Cryptaxis alloporoides, to the Madri- 

 poridece. Fragments of other species have, however, been found 

 too imperfect to describe, and authors have also quoted some which 

 Prof. Eeuss has not had an opportunity of examining ; the whole 

 number is therefore probably greater. The author then gives a 

 detailed account of the different species at present known to him. 



3. Bryozoa. — These are much more numerous in the Cassel beds 

 alone. The author is already acquainted with 73 species, and there 

 are probably others. A tabular statement of their different locali- 

 ties then follows, from which it appears that they are very un- 

 equally distributed. Thirty-seven species have been found at Ast- 

 rupp and 28 at Luithorst. It is, however, worthy of notice, that 

 many of these Bryozoa extend through several stages of the Ter- 

 tiary formation, and they must therefore have continued to exist 

 through a long period of time. This is in direct opposition to the 

 opinion of E. A. Eomer, who has stated that each species of Bryozoa 

 is peculiar to one Tertiary formation, and that any one Bryozoon is 

 sufficient to fix the age of the formation in which it is found. This 

 Prof. Eeuss considers to be an error. Then follows the detailed 



