34 INVERTEBRATE ZOOLOGY 
Exercise 12. The two pairs of delicate appendages in front of 
the maxillipeds are the maxille; they are cephalic append- 
ages. Remove with forceps the right-hand second maxilla 
and draw a large outline of it. The protopodite is wide 
and leaf-like; the endopodite is small; the exopodite is 
wide and with the epipodite forms a broad plate, called the 
scaphognathite, which is used by the animal to maintain a 
current of water from the gill-chamber. 
Exercise 13. Remove carefully and draw the right-hand first 
maxilla. The protopodite is wide and leaf-like 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. Close to the posterior surface of 
the mandibles are the delicate paragnatha. 
Exercise 15. Remove at its base and draw the right-hand second 
(the longer) antenna. The exopodite is a short, stiff, plate- 
like 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 endopo- 
dite are present in this appendage throughout the Crustacea, 
there being typically but one terminal branch. In the cray- 
fish 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: 
