26 



PHYLUM ARTHROPODA 



Exercise 13. Remove carefully and draw the right-hand first maxilla. 

 The protopodite is wide and leaflike and similar to that of the 

 second maxilla ; the endopodite is extremely small ; the exopodite 

 is wanting. 



Exercise 14. Extract with strong forceps and draw the right-hand 

 mandible. The biting portion of it, together with the first joint of 

 the small palp, forms the protopodite ; the two terminal joints of 

 the palp are the endopodite ; the exopodite is wanting. 



Exercise 15. Remove at its base and draw the right-hand second 

 (the longer) antenna. The exopodite is a short, stiff, platelike 

 expansion ; the endopodite is the long, slender, terminal portion. 



Exercise 16. Remove and draw the right-hand first antenna, or 

 antennule as it is also called. No exopodite and endopodite are 

 present in this appendage throughout the Crustacea, there being 

 typically but one terminal branch. In the crayfish and lobster this 

 terminal branch is double. 



Exercise 17. Construct in your notebook a table showing the relation 

 of the appendages and somites, as follows : 



