joined in strings by these projections. Make a draw- 

 ing representing several eggs connected. 

 (5). Make a drawing of the left side. 

 (6). Make a drawing of the left side. 

 (12). Make outline sketches of the dorsum and venter of the 

 sktill, and compare with the skull of No. 8. Point out 

 the distinctive features. In tracing the specimen to 

 its family, you will find names for the distinctive 

 structures. These constitute family characters. 

 This jar contains both male and female. Note that 

 in the male, the vent is swollen; the legs are 

 wider and stronger than those of the female; the 

 palmar surface of the toes and the inner side of the 

 ankle possess patches of a dark horny substance. 

 These are secondary sexual characters and aid the male 

 in holding the female while mating. The patches are 

 present only dtiring the breeding season. The tail 

 crest of the male is much larger than that of the 

 female. 

 Make a drawing of the sole of the foot and the inner side 

 of the leg, and of the lateral aspect of the tail and vent 

 of both sexes. 

 (13). Eggs of No. 12. Make a drawing of the eggs and 



the plant to which they are attached. 

 (15). Eggs of No. 14. Drawing of the egg-mass. 

 (16). Specimens illustrating the larval and transformation 

 periods of No. 14. 



(a). Mature larva. Drawing of the left side, 

 (b). Transforming larva. Note changes on the 

 exterior, and draw the left side. 

 (17). The shoulder girdle of the frog, illustrating the type 

 found in the Firmisternia. The girdle is here con- 

 sidered as composed of an axial portion and two 

 lateral portions or wings. 



(a). The axial portion — The episternum is a spade- 

 shaped piece of calcified cartUage, and is the 

 most cephalic of the axial pieces. Its edges 

 are very thin and composed of imchanged 

 hyaline cartilage. The xiphisternum is the 

 most caudal of the axial elements; In shape 



IS 



