ANCIENT SLA TE-INSCRIP TIONS. 



55 



as a free swimming animal, a sort of jelly fish, 

 which, however, soon settles down and proceeds to 

 establish a colony. Fig. 11 shows the magnified 

 calycles, and also a much enlarged reproductive 

 capsule of the common Sea-fir (Sertularia abietina). 

 For the purpose of 

 comparison a por- 



tion of graptolite is 

 added at Fig. 12, 

 showing a magni- 

 fied view of what 

 are regarded as cor- 

 responding to the 

 calycles or cells of 

 Sertularia. 



It is probable 

 that Graptolites 

 were in some re- 

 pects similar to 

 these Sea-firs. The 



double Graptolites (Fig. 13) look rather like Sea- 

 pens (Pennatula). This led Page to regard them 

 as allied to these members of the order of Actinozoa, 

 but the resemblance is merely 

 external. Others have ranged 

 the Graptolites amongst Polyzoa, 

 which gives them a still higher 

 y,. development, but there is very 

 chisoni. little justification for this. Few 



palaeontologists or zoologists are more competent to 

 decide such a question than Professor Nicholson of 

 Aberdeen, who makes them a sub-class of Hydrozoa, 



FIG. 11. Sea-fir (Sertularia aMetind) 

 with magnified calycles and capsule. 



