On the Constrictor Dorsalis Muscles of Sphenodon

Abstract

tionship among species. The primary basis for establishing genera is morphological distinctiveness; however, it is usually supplemented by data on ontogeny, behavior, mode of life, adaptive trends within the group, etc. In view of the numerous, fundamental differences in morphology, ontogeny, and ecology discussed in this report, the genus Gyrinophilus is valid. Such recognition best indicates the relationship of these animals to other plethodontids. Acknowledgments. -We are grateful to Charles F. Walker, University of Michigan Museum of Zoology, for making available specimens of Hemidactylium scutatum and Plethodon glutinosus; to Dave Wake, University of Southern California, and to Doris M. Cochran, U. S. National Museum, for specimens of Gyrinophilus porphyriticus; and to Albert P. Blair, University of Tulsa, and James N. Dent, University of Virginia, for the specimens of G. palleucus.