370 Coe and Kunkel— California Limbless Lizard. 
The mandible is made up of the articular (fig. 7, a), angular, coro- 
nary (cor), dentary (fig. 7, dv and fig. 8), and splenial (sp). The 
articular is co-ossified with the supraangular. The angular is flat and 
splintlike, situated on the external aspect of the mandible, external 
to the articular and dentary. Eight teeth are usually borne on the 
dentary. They are acutely conical, grooved on the inner surface 
and directed slightly backwards. 
The hyoid apparatus is, according to Cope, the simplest among the 
lizards: it consists of a continuous glosso-hyal rod, which is bifurcate 
posteriorly, and a simple branchihyal attached to each of the 
branches. The other elements are wanting (pl. xxu, fig. 12). 
Vertebre.—The vertebre are procelous. The presacrals vary in 
number from 71 to 74, and all have simple ribs attached except the 
first two. Ina single specimen Baur found that there was a short 
rib present on one side only of the second vertebra. The neural 
spines are well developed and directed posteriorly (pl. xxu, figs. 21 
and 22). No zygosphene is present on the cervicals, which are dis- 
tinguished by the presence of ventral processes. The processes 
diminish posteriorly, and that of the first vertebra is bilobed. The 
transverse processes arise from the anterior portion of the vertebra 
(fig. 19): 
There are four sacral vertebre with no ribs attached, but with. 
the transverse processes much developed. The first has a simple 
process directed slightly backwards; the second has the process 
split distally, the posterior prong being smaller and variable in posi- 
tion. The third has the same form as the second, but the notch at 
the extremity of the transverse process is deeper. It also shows the 
first indication of a chevron in the form of two parallel plates placed 
lengthwise on the ventral side of the centrum and not uniting dis- 
tally. In one specimen these plates were wanting. The fourth is 
similar to the third but the chevron is complete. Baur (’94) found 
the chevron incomplete as in the preceding and the splitting of the 
transverse process only on one side. The first caudal and all the 
succeeding have simple caudal ribs, diapophyses, directed anteriorly, 
and completely formed chevrons pointing posteriorly. The chevrons 
are situated at the posterior ends of the centra and not intercentrally. 
The transverse splitting of the vertebre in the tail commences at 
the third caudal. A portion of the base of the transverse process is 
included in the small anterior segment; the posterior segment is pro- 
celous (figs. 23 and 24). The number of caudals varies. In one 
specimen with a moderately long tail there were 36. 
