•24 



Recapitulation. 



Number t)f species. 



Cambrian. 



Lower 

 Silur. 



Total. 



Crustacea. Trilobitae 



Phyllocarida 



Ostracoda 



Cirrhipedia .. 



Annelida 



Mollusca. Cephalopoda 



Pteropoda ... 



Gastropoda .. 



Pelecvpoda .. 

 Molluscoidea. Brachiopoda 



Bryozoa 



Echinoderma Cystidea 



Coelenterata. Acalepbse 



Anthozoa 



Spongiae 



Graptolithae. 



109 



2 



5 

 1 



17 



256 

 2 

 7 

 1 

 1 



50 

 3 



32 

 9 



72 



10 

 •23 



17 



1 



143 



365 

 2 



9 

 1 

 1 



50 

 8 



33 

 9 



.S9 



10 



17 



2 



140 



Total' 



141 



627 



768 



There is not a single species recorded as common between the Cambrian 

 and the Lower Silurian formations, but the latter have 19 species which also 

 occur in the L^pper Silurian beds. In the present state of our knowledge .some 

 elements of error cannot possibly be avoided. Upon the whole only the Trilo- 

 bites, the Graptolites and the Anthozoa are worked out, but the former two 

 orders are no doubt in need of a thorough revision. Of the Cystideans, the 

 Cephalopoda, the Brachiopoda and the Bryozoa there is fresh material and rela- 

 tively little work done. The species of Gastropoda and Pelecypoda are scarce 

 and badly preserved, 



1 have had the advantage of Dr Tornquist's aid in looking over the Graptolites. 



Stockholm, Januarv 28*^ 1888. 



G. Lindstrom. 



