Immediately following the thirty-fifth rib-bearing vertebra there is an abrupt change, the tubercular process for the rib giving place to an elongated transverse process. From the position of the pelvis, it is evident that the ilia were attached to the first pair of these. Precisely this relation of pelvis to the vertebrae is found in such lizards as the Monitor and Iguana, and it is probable that such is the relation in all the Pythonomorpha. It will thus be seen that there are no distinctively lumbar vertebrae, if by such are meant free, non-costiferous, pre-sacral vertebrae. The vertebrae of these animals that have been so designated by writers are in reality basal caudal. A distinctive term for them—those with transverse, non-costiferous processes and without chevrons—is needed, and we propose, provisionally, the term _pygial_. There are seven in the present series, all characterized by elongated transverse processes, and not differing much from each other. The vertebrae lie in the matrix with the ventral aspect uppermost, concealing the spine and upper parts. The under surface is somewhat flattened, and, as in the preceding vertebrae, is gently concave antero-posteriorly. The transverse processes are elongate, stout towards the base, apparently all of nearly equal length, and directed gently backwards and downwards. In the anterior vertebrae the processes spring from near the front part: as the centra become shorter they arise from near the middle. In the last one of the series there are minute indications of chevrons. MEASUREMENTS OF THE PYGIAL CAUDAL VERTEBRAE. 1. Length to rim of ball 36 millim. Width of ball 25 Expanse of transverse processes 130 Width of transverse process near base 17 2. Length to rim of ball 33 3. Length to rim of ball 31 4. Length to rim of ball 29 5. Length to rim of ball 28 6. Length to rim of ball 27 Expanse of transverse processes 130 Width of ball 24 7. Length to rim of ball 27