300 OUR COMMON BRITISH FOSSILS. 



nites should be regarded as belonging to that group 

 of animals which, rightly or wrongly, has for years 

 occupied the leading position of the Invertebrates. 

 Nautiluses and "cuttle-fishes" still figure at the top 



Fig. 297. Lituites articulatus. 



Fig. z<)6.Orthoceras, upper 



part shows chamber perfor- rJg. =98. Cyrtoceras Murchisoni 



ated by siphuncle. (Silurian). 



of this division, and many students accept that posi- 

 tion as indicating their higher zoological rank. Many 

 philosophical naturalists doubt this, but meantime we 

 must accept it, for classification purposes at least. 



