KEY TO PHYLA 



3. (2) Scales or plates moist (rarely absent, in these cases 

 distinguishable by presence of rayed fins). Rayed fins always 

 present. Breathe by gills CLASS PISCES 



4. (i) Body not covered with scales 5 



5. (6) Cold blooded, skin slimy CLASS AMPHIBIA 



6. (5) Warm blooded 7 



7. (8) Body covered with feathers CLASS AVES 



8. (7) Body covered with hair ~ CLASS MAMMALIA 



REFERENCE 



Ward, Henry B. and Whipple, George C., 1918. Fresh W 7 ater 

 Biology. John Wiley and Sons, Inc. 



Lutz, Frank E., 1921. Field Book of Insects. Revised. G. P. 

 Putnam's Sons. 



