_Referred specimens._--K. U. nos. 786F, 787F, 788, 9939,
11424, 11425, 11426, 11427, 11428, 11429, 11430, 11431,
11432, 11433, 11434, 11449, 11450, 11451, 11452, 11453,
11454, 11455, 11457.

_Preservation._--Preservation of many of the specimens is
good, few are weathered, but most of the remains are
fragmentary and dissociated. One specimen (the type, no.
786F) and half of another were nearly complete. Specimens
are found scattered throughout the Rock Lake shale (see p.
498).

_Morphology._--Terminology used for bones of the skull is
that of Moy-Thomas (1937) and Schaeffer (1952).

_Endocranium and parasphenoid_

[Illustration: FIG. 1. _Synaptotylus newelli_ (Hibbard). Restoration of
the basisphenoid, based on K. U. no. 9939, x 5. A, lateral view, B,
posterior view, C, ventral view.]

The basisphenoid (see fig. 1) has been observed in only one specimen (K.
U. no. 9939) in posterodorsal and ventral views. The basisphenoid,
although somewhat crushed, appears to be fused to the parasphenoid. Both
antotic and basipterygoid processes are present, and are connected by a
low, rounded ridge. The antotic processes are large, bulbar projections.
These processes in _Rhabdoderma_ are wider and more flattened
(Moy-Thomas, 1937:figs. 3, 4). The antotic processes are at mid-point on
the lateral surface, not dorsal as in _Rhabdoderma_, and both the
processes and the ridge are directed anteroventrally. The basipterygoid
processes are smaller, somewhat vertically elongated projections,
situated at the end of the low connecting ridge extending
anteroventrally from the antotic processes, and are not basal as are
those of _Rhabdoderma_. The sphenoid condyles, seen in posterior view,
issue from the dorsal margin of the notochordal socket. The margins of
the socket are rounded, and slope down evenly to the center. A slight
depression situated between and dorsal to the sphenoid condyles is
supposedly for the attachment of the intercranial ligament (Schaeffer
and Gregory, 1961:fig. 1). The alisphenoids extend upward,
anterodorsally from the region above the sphenoid condyles, and may
connect to ridges on the ventral surface of the frontals. The lateral
laminae are not preserved, and their extent is unknown.

In viewing the changes in the endocranium of Carboniferous and Permian
coelacanths, it would be well to consider the mechanical relationship of
the loss of the basipterygo