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1. Cross-embrace of a male Bufo lentiginosus americainis with a dead female Rana pii>iens. 



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 showinp: 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 versicolor showing the axillary type of amplexation, where fingers 



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



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



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



