452 R. Lydekker— Catalogue of Fossil Reptilia, ete. 
glad to take an early opportunity of correcting. I am also indebted 
to Dr. Baur for pointing out a less excusable error in regard to the 
serial position of Geosaurus. 
At the same time I take the opportunity of adding some 
observations regarding my papers on the Ichthyopterygia and 
Sauropterygia published in the July and August numbers of this 
Macazinz, which were written in the hope of inviting criticism of 
which advantage might be taken in the second part of the Museum 
Catalogue. 
In the diagnosis of the Pythonomorpha, Prof. Cope has been 
followed ; and I have omitted to notice that Prof. Marsh’ has figured 
a sternum in one genus. Following Owen? and Pictet* Geosaurus 
is placed in the Pythonomorpha. Wagner has, however, pointed 
out its relationship to Cricosaurus. In the crushed vertebree of the 
type one of the transverse processes has been mistaken for the 
neural spine; and the apparently proccelous character of some of 
the centra seems to be due entirely to the effects of pressure. The 
vertebra, indeed, are truly Crocodilian; and it seems that the genus 
(with which Cricosaurus is probably identical) should form the type 
of a distinct subfamily of Crocodilia, characterized by the presence 
of a sclerotic ring, and the absence of a lateral vacuity in the 
mandible. This subfamily Geosaurine should be placed next the sub- 
family Metriorhynchine of the Teleosauride, since the skull of 
Cricosaurus is essentially of the type of that of Metriorhynchus ; 
with which genus I had, indeed, proposed to identify it. From the 
similarity in the teeth it is possible that Pristichampsa, of the Lower 
Eocene, may prove to be a late survivor of the Geosaurine. 
The vertebra of Bothriospondylus suffosus appeared to me to resemble 
the figure of the vertebra of Creosaurus, but Prof. Marsh states that 
they undoubtedly belong to an immature member of the Sauropoda, 
which may be identical with one of the Kimeridgian species of 
Ornithopsis. The vertebra of B. robustus is probably also referable 
to the same suborder, and may belong to an immature Cetiosaurus. 
The two calcanea provisionally referred on p. 225 to Iguanodon 
are also recognized by the same authority as Sauropodous. The 
teeth provisionally assigned by Sir R. Owen to Hyleosaurus, and 
entered on p. 185 under that heading, Prof. Marsh recognizes as 
undoubtedly Sauropodous, having some resemblance to those of 
Diplodocus. This would remove any bar to Sir R. Owen’s identification 
of Regnosaurus with Hyleosaurus; but the former may equally well 
be identical with the later Polacanthus, although probably too large 
to belong to Vectisaurus, on the assumption that the latter belongs 
to the Scelidosauride. Assuming that these teeth are truly Sauro- 
podous, the small size of the tooth referred by Phillips (and probably 
correctly) to Cetiosaurus Oxoniensis suggests that they may belong to 
the smaller C. brevis, which would then be proved to differ widely 
from Ornithopsis (? Pelorosaurus), which had large teeth. 
1 Amer. Journ. ser. 3, vol. xix. pl. i. (1880). 
2 Odontography, p. 268. It is pointed out that the vertebre approximate to the 
Crocodilian type. 
3 Paléontologie, 2nd edition, p. 506. 
