Fishes. 17 



of sand, about fiftj- feet from the receding tide. If tlie reader 

 should be fortunate enough to meet with this creature, he must 

 bear in mind that he has before him one of the classical types 

 of zoology, about which more has been written than on anj^ 

 other of low standing, and which has given rise to much co)i- 

 troversy among evolutionists, some regarding it as a connecting 

 link between Invertebrates and Vertebrates, others endeavour- 

 ing to demonstrate that it is derived by degeneration from the 

 latter. 



