20 A MANUAL OF ZOOLOGY 



note its direction. Has it an exopodite? Note the male 

 genital aperture. On what segment does it open? Make 

 a drawing of this appendage. Carefully remove the next 

 appenaaie"'anH"compare it with the one just studied. Does 

 it have a gill? An epipodite? In female specimens of 

 lobsters, note the receptive apparatus near the base of the 

 coxopodite. Make a drawing_of this appendage. Remove 

 the next appendage and compare with the one just studied. 

 How does the distal end differ from the other? Note the 

 female genital pore in the coxopodite. Draw_as, .abpx^^ 

 Compare the next appendage in every respect with the 

 ones just studied. Remove the- great chela. Compare with 

 the other appendages and with each other on the same 

 and different specimens. Is the distribution of hairs on 

 both chelae alike? What differences are found? Note the 

 teeth, are they alike on both jaws? Remove the next 

 appendage; the third maxiliiped pr foot jaw. Compare 

 with the great chela. Remove the next two appendages, 

 the second and the first maxiijlpeds. In ar review of all 

 of the thoracic appendages note the two groups into which 

 they naturally fall. The next ai>pendages may be called 

 the head appendage?. Remove the ,#iext one, the second 

 maxilla. Are there any modifications? The large plate 

 like expansion is known as the'scaphognathite. Remove 

 the next appendage, the first maj^JHrf. "compare with the 

 preceding. 12£5Z!!^_?2£fc_9l-J-?®_™^^i'l%-6- The mandible 

 is the next appendage. Note the'paTpus, themetastoma, 

 and the labrum. What is the direction of the mouth open- 

 ing? Remove tjie next two appendages, the antenna and 

 the antennule. At the base of the antenna note the open- 

 ing of the green gland. Examine the antennule for the 

 opening of the auditory organ. Compare these two ap- 

 pendages in every respect. The eyestalk is sometimes 

 called an appendage. Make a review of all the appendages, 

 noting any differences or likenesses. Decide as to the 

 advantage of each to the animal. What constitutes the 

 boundary of the gill chamber? The gills may be classed 

 as podobrarichiae, arthrobrarichiae, and pleurobrancliiae. 

 What is tjie basis of this classification? How many of 

 each of the classes of gills are there? Study a gill in 

 water for its structure.. Some of the. gills referred to 



