WRIGHT 



PLATE IV 



. 





1. Cross-embrace of a male Bufo lentiginosus amerieanus with a dead female Rana pipiens. 



The amplexation is pectoral, not axillary. X0.5. 



2. Cross-embrace of a male Rana pipiens with a female Rana palustris. The pair captured 



in the field in a mated condition. X0.5. 



3. A female Rana pipiens showing the effects of 17 days' pectoral amplexation. XI. 



4. A mated pair of Rana pipiens showing pectoral (Rana) type of amplexation. X0.75. 



5. A pair of male Hyla veisicolor showing' the axillary type of amplexation, where lingers 



are folded back in the embracing male. X0.75. 



6. A mated pair of Rana clamata, the small male holding axillai y-like on the right side and 



partly pectoral-like on the left side. X0.5. 



