CRUSTACEA OF THE PAST 



265 



Melbourne, and of the fossil Prceanaspides (Fig. 85) 

 from the Coal-measures of Derbyshire, have tended 

 to support this conclusion. There can be httle 

 doubt that the Syncarida arose during the Carbon- 

 iferous epoch (or earlier) from primitive shrimp-like 

 forms which lost the carapace ; but, after flourishing 

 for a relatively brief period, the group dwindled away, 



Fig. 85 — PrcBanaspides precursor, One of the Fossil Syncarida, 

 FROM THE Coal-measures of Derbyshire. Slightly en- 

 larged. (After H. Woodward.) 



although a few survivors have lingered on, like so 

 many other " living fossils," in the isolated Australian 

 region. 



It must be pointed out that, in spite of the re- 

 semblance of the body of Anaspides to that of an 

 Amphipod, the Syncarida can have had no close 

 relation to the origin of the Isopoda and Amphipoda. 

 These have also been derived from a shrimp-like 

 type, but their possession of a brood-pouch, among 



