All specimens are in the University of Kansas Museum of Natural History. The catalogue number of each specimen, and the legs of it that were dissected, are listed below. T.p. 1L,R KU38520 T.c.p. 4L KU38518 T.p. 2L,R KU38521 T.c.a. 1L,R KU36617 T.p. 3L,R KU38522 T.c.a. 2L KU36618 T.p. 4L KU38523 P.p. 1L,R KU38526 T.p. 5R KU38524 P.p. 2L KU38527 T.c.p. 1L,R KU38515 P.p. 3L,R KU38528 T.c.p. 2L,R KU38516 P.p. 4L KU38529 T.c.p. 3L KU38517 The specimens were injected in the field either with formalin (10%) or embalming fluid, except for those of _T. c. attwateri_, which were frozen; the latter were later injected with embalming fluid. Injection in all the birds was by hypodermic syringe into all major muscle masses, into the body cavities, and subcutaneously in the neck, wings, and feet. In those specimens injected with embalming fluid, the body cavities were injected with formalin. The embalming fluid consisted of 70 per cent alcohol, glycerin (or propylene glycol), and formalin (full strength) in the approximate ratio of 78:20:2, respectively. This fluid gave good preservation; these specimens had the advantages of lacking almost entirely the irritating odor of formalin and of having pliable tissues. The skin of those specimens originally injected with formalin was slit in several places and they were transferred to crocks containing embalming fluid (without the formalin). After a period of many weeks, with two changes of fluid, most of the formalin odor was eliminated and the muscles were sufficiently pliable to be easily dissected. All specimens were kept in containers filled with embalming fluid. No mold ever appeared, even though no phenol or other chemical was added. To facilitate comparison, two or three specimens were frequently dissected simultaneously. The nerves and smaller muscles were dissected with the aid of a stereoscopic microscope mounted on a long movable arm. In order satisfactorily to expose the lumbosacral plexus the posterior half of the sternum and pectoral muscles, as well as the abdominal viscera, were removed. To insure more nearly accurate proportions, drawings of the pelvis and of some of the muscles were made with the aid of photographs of the several specimens listed above. TERMINOLOGY _Skeleton_