PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 435 



sub-carboniferous and devonian, and prepare a table (No. 2,) comparing 

 and collating the primordial with the middle and upper silurian, remarking 

 that the boundary between the two is more shadowy and dimly defined than 

 between the later silurian and carboniferous, for the appearance of fish and 

 reptiles in the latter give a line of demarkation apparent to the most super- 

 ficial observer. 



Examination of this table shows the following genera and species descen- 

 ding from the Primordial into the succeeding Silurian, viz: of marine plants 

 the Pirimordiae had 5 gen., 2 of which were continued into the silurian seas; 

 of Protozoa II gen., 2 of which passed onwards, and 68 species, 2 only sur- 

 viving the changes attending the laying down of the Potsdam S. S.; of 

 Annelidse it had 3 gen, 2 of which were continued ; of Bryozoa 1 gen, which 

 was continued; of Echinodermat^ 2 gen., with 1 continued; of Cephalopodae 

 4 gen., all continued; of Gasteropoda 17 gen., 15 of which were continued; 

 of Brachiopodse 12 gen., all were continued; of Conchiferse 9 gen., 5 of 

 which descended; and of Articulata 12 gen., only 1 descending into the Si- 

 lurian. 



There haf e been lost in this earliest period of transition from one epoch 

 to another, 32 genera and 255 species. 



Let us now examine the table in another light, looking for the new crea. 

 tions. This table of Silurian Fauna exhibits only that portion of it which 

 is intimately associated with the primordial, often reposing upon it, and 

 never separated from it but by a few thousand feet. 



The Silurian has of plants 1 new gen and 7 spec; Protozoa 5 gen. and 16 

 spec; Annellidfe 2 new spec; Foraminifera 3 gen. and 11 spec; Bryozoa 11 

 gen. and 34 spec; Echinodermat^ 39 gen. and 102 spec; Cephalopodas 10 

 gen. and 128 spec; Gasteropodse 9 gen. and 144 spec; Brachiopodas 6 gen. 

 and 178 spec; Conchiferaj 11 gen. and 85 spec; Crustacese 31 gen. and 111 

 spec; and of Tunicatse 1 gen. and 1 spec. 



The sum total of two new orders, 138 new genera and 863 new species. 

 The excess of births over deaths, of two orders, 108 genera and 608 species. 



As in the carboniferous, so also in the silurian, the argument from Palae- 

 ontology is negative against the Darwinian hypothesis. 



The gradual development theorists may reply, by saying, that between 

 the primordial and middle silurian, there was a long interval of time — quite 

 long enough to establish their position of the evolving of species by a 

 struggle for existence — "For the rocks," they say, and truly so, " are filled 

 with the exuvias of the ancient dead. An innumerable host; and during 

 this multiplication of the number of individuals, in this wide lapse of time, 

 there may have been a lineal descent of species from a common ancestry." 



To this insidious and argumentative inquiry, we answer: We may go 

 back to the earliest of American fauna — as low down in the Taconic rocks 

 as Dr. Emmons has discovered any evidence of palaeozoic life, and here, on 

 the very first tablet of the stony record, side by side, as if cotemporaneous 

 in life and death, lie Zoophytae, Cephalopodae, Gasteropodae, Pteropodae, 

 Brachiopodae, Conchiferae and Crustacese, with marine plants. A fauna, 

 quite sufficient to supply carbon to the plant-lite, and a fucoidal flora, 

 equally sufficient to supply oxygen and phosphorus, with sustenance to the 

 animal life. 



