CONTENTS 



PAGE. 



Introduction 1 



The region studied and the methods 



pursued 2 



A catalogue of the Ithacan Anura ... 3 



General account of the Ithacan 



Anura 4 



First appearance 4 



Mating 6 



Customary amplexation 8 



Cross-embraces 8 



Abnormal embraces 9 



Departures from the customary am- 

 plexation and their significance . 9 



Ovulation 11 



Eggs 15 



Key to the eggs of the Ithacan 



Anura 18 



Hatching period 19 



Larval period 19 



Mature tadpoles : 20 



Key to the tadpoles 22 



Transformation 24 



Affinities of our eight species 25 



Life-history of the American Toad, 



Bufo lentiginosus americanus ... 26 



First appearance 26 



Voice 27 



Mating 28 



Ovulation 29 



Egg-laying process 31 



Eggs 32 



Hatching period 32 



Mature tadpole 33 



Larval period 33 



Transformation 33 



Autumnal disappearance 34 



Life-history of the Peeper, Hyla 



pickeringii 35 



First appearance 35 



Voice 36 



Mating 37 



Ovulation 38 



Egg-laying process 39 



Eggs.. 40 



Hatching period 41 



Mature tadpole 41 



Larval period 42 



Transformation 43 



Autumnal disappearance 43 



Life-history of the Tree-toad, Hyla 



versicolor 44 



First appearance 44 



Voice 45 



Mating 46 



Ovulation 47 



Egg-laying process 48 



Eggs 49 



Hatching period 49 



Mature tadpole 50 



Larval period 51 



Transformation .51 



Autumnal disappearance ol 



Life-history of the Meadow-frog, Rana 



pipiens 52 



First appearance 52 



Voice 53 



Mating 54 



Ovulation 55 



Egg-laying process 57 



Eggs 57 



Hatching period 58 



Mature tadpole 58 



Larval period 59 



Transformation 59 



Autumnal disappearance 60 



Life-history of the Pickerel-frog, Rana 



palustris 61 



First appearance 61 



Voice 62 



Mating 62 



Ovulation 64 



Egg-laying process 65 



Eggs 66 



Hatching period 67 



Mature tadpole 67 



Larval period 68 



Transformation 69 



Autunmal disappearance 69 



Life-history of the Green-frog, Rana 



clamaia 70 



First appearance 70 



Voice 71 



Mating 71 



Ovulation 72 



Egg-laying process 73 



Eggs.. 73 



Hatching period 75 



Mature tadpole 75 



Larval period 76 



Transformation 76 



Autumnal disappearance 76 



Life-history of the Bullfrog, Rana 



catesbeiana 77 



First appearance 77 



Voice 78 



Mating 79 



Ovulation 80 



Egg-laying process 81 



Eggs. 82 



Hatching period 83 



Tadpoles 83-84 



Larval period 85 



Transformation 85 



Autumnal disappearance 86 



Life-history of the Wood-frog, Rana 



sylvatica 87 



First appearance 87 



Voice 88 



Mating 89 



Ovulation 90 



Egg-laying process 92 



Eggs 94 



Hatching period 95 



Mature tadpole 96 



Larval period 97 



Transformation 97 



Autumnal disappearance 98 



