THE RECORD FROM FOSSILS. 



JO/ 



Of the history of the unsegmented worms we know nothing through 

 geology, for their soft bodies have never been preserved. From their 

 anatomical position we conclude that they are very ancient animals, 

 and have doubtless lived through all geological ages. 



CO M Br A PI 



FIG. 12. Diagram illustrating the history of the Crustacea. C Cirrepedia. 

 O Ostracoda. M Macroura. Br Bracyura. A Amphipoda. P Phylocarida. 

 / Isopoda. 



ARTICULATA. 



This large division of animals includes two provinces. 



Anarthropoda (segmented worms). The worms have soft bodies, not 

 adapted for preservation as fossils. Some of them, however, live in 

 tubes of lime or sand, and these cases are often preserved. Occasionally 

 we learn of their existence by their tracks on the ancient mud. From 

 such sources we know that they were in existence, well differentiated, 



