54 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE 
The ‘ Squamosal.”—This bone has been most fully described by Baur, who? has 
accurately dealt with its relationships to the parietal, postorbital, jugal, quadrato-jugal, 
quadrate, and paroccipital process. It is unnecessary here to recapitulate the details 
of this association, which our figures render sufficiently clear, except to remark that 
we have extended the relationship to the pterygoid. 
In the progress of investigation into the comparative osteology of the fossil reptiles, 
the varying conditions of the squamosal and supratemporal, one or both of which may 
be present, have become the subject of much consideration. ‘The presence of the two 
has been regarded as a lowly characteristic, if only by way of analogy to the Stego- 
cephalia. Cope and Baur are conspicuous among those who have utilized these bones 
in the determination and discussion of affinity, and nothing short of a deplorable 
confusion has arisen from their inconsistency in the usage of terms *, and the fact that 
while one of them arrived at an inversion of the order adopted by certain contemporary 
writers, he finally complicated matters® by needlessly reviving for the reptilian 
squamosal Owen's term “ prosquamosal.” A final agreement was never arrived at, and 
the question therefore arises as to which of the two bones is for the future to be 
regarded as the supra-temporal. 
As a general rule these bones lie side by side in the same transverse plane. The 
term supra-temporal was applied by Bakker to the inner one‘, in dealing with the fish 
skull. Cuvier denoted the presumably homologous bone in reptiles the ‘“‘mastoid”°; and 
Owen, retaining this term, applied ® to the outer of the two (Cuvier’s “temporal ”’) the 
term squamosal. To be consistent, therefore, on the assumption that the inner of the 
two bones, having similar relationships in fishes and reptiles, is homologous, 
convenience and precision are met by terming the inner the supra-temporal, the outer 
the squamosal. And it is in this sense that we use these words *. 
Our knowledge of the paleontological history of the Rhynchocephalia has during 
recent years been materially advanced by the description by Lortet of remains from 
the Jurassic of France. In his memoir already cited (antea, p. 3) he drew attention 
in Sapheosaurus (Sauranodon) to a “ parieto-squamosal” complex, in respect to which 
1 Baur, G.: Anat. Anz. Bd. x. 1895, p. 321. 
* Of. Baur, G.: Anat. Anz. Bd, i. 1886, p. 349, and Bd. ii. 1887, p. 657! and, as an awful example, the 
series of notes embodying the dispute between him and Cope in Amer, Nat. vols. xxix. & xxx, 
* Baur, G.: Anat. Anz. Bd. x. 1895, p. 320. 
* In Cuvier and Valenciennes, Hist. Nat. des Poissons, t. i. 1828, p. 338. 
° Cuvier, F.; Ossemens Fossiles, t. x. 1836, p. 14. 
® Owen, R.: Catal. Osteolog. Series R. Coll. Surgeons, vol. i. 1853 (table), p. xxxviil. 
7 Concerning the afore-mentioned confusion, Fraas for example, in his revisionary memoirs on the Ichthyo- 
sauria and Stegocephalia, following in respect to the latter the lead of Huxley, Miall, Fritsch, and Credner, 
refers to the inner bone as the squamosal, the outer as the supra-temporal, Zittel adopts the Huxleyean 
order for the Reptilia and Stegocephalia, with confusion arising out of the interpretation of the latter in the 
Lacertilia as the quadrato-jugal. Briihl is still more glaringly inconsistent and contradictory ; while even 
