34 CRUSTACEA 



(c) Location? 



(d) Number of segments? 



(e) Covering? 



(f) Parts. (Take out one, sketch it, see Huxley or other 



large zoology, and name all the parts present.) 



(g) Use? 



(6) The Antennules. (a)-(g) as for antennse. 



(7) The Mandibles, or Jaws. A pair of hard toothed ap- 



pendages. 



(a) Shape? 



(b) Location? 



(c) Motion? Horizontal or vertical? 



(d) Use? 



(e) Mandibular palpi. Number to each mandible? 



(f) Metastoma, a leaf-like structure posterior to each 



mandible. 



(8) The MaxillaB — two pairs of thin appendages just poste- 



rior to the m.andibles. With your forceps carefully 

 remove them from one side. Be careful not to in- 

 jure them. 



(a) Shape? 



(b) Use? 



(c) Sketch each, much enlarged. 



(9) The Maxillipeds — three pairs of similar appendages be- 



tween the maxillae and the large legs. 



(a) With forceps carefullj^ remove the maxillipeds from 



one side. Sketch each one, much enlarged. 



(b) Use? 



(10) The Legs. Five pairs. 



(a) Remove the large leg on the right side and sketch it. 



(b) How many segments has it? 



(c) Sketch shapes into which you can arrange this 



''toggle-jointed" appendage. 



(d) Use? 



(e) Compare it with the second pair of legs, noting 



points of similarity and difference. 



(f) Compare with the third pair. 



(g) Compare with the fourth pair, 

 (h) Compare with the fifth pair. 



