1886. ] ON THE COLUMELLA OF ICHTHYOSAURUS. 405 
10. Note on the Presence of a Columella (Epipterygoid) in 
the Skull of Ichthyosaurus. By A. Smrra Woopwarp, 
F.G.S., of the British Museum (Natural History). 
(Communicated by Professor Frowrr, LL.D., F.R.S., 
President.) 
[Received June 3, 1886.] 
In the skulls of fossil Reptiles and Amphibia it so rarely happens 
that the bones on the inner side of the temporal fossa, and those 
between the orbits, are well exposed to view, that even in some of 
the most familiar genera very little has yet been ascertained regarding 
the special characters of any of these ossifications. In so conspicuous 
a form as Ichthyosaurus, for example, there appears to be no published 
reference to these structures beyond the brief statements of Profs. 
Huxley, Cope, and Sir Richard Owen, and even these do not afford 
any very definite information. Prof. Huxley determined’ the 
presence of a distinct pro-otic, and the doubtful absence of ali- and 
orbito-sphenoids ; Prof. Cope gives* a diagrammatic outline of the 
“ columella” ; while Sir Richard Owen appears to have been less 
successful in his researches, having met with nothing but unsatisfac-. 
tory indications of small ‘‘alisphenoids” (? pro-otics), and especially 
remarking that there is “ no trace or sign of the Lacertian columellar 
bone”’’. ; 
In making the latter statement, the distinguished paleontologist 
just mentioned evidently overlooked Prof. Cope’s previous researches 
upon the osteology of the Ichthyosaurian skull; and having lately 
discovered that there is no foundation for the assertion in the British 
Museum specimens, that formed the basis of Sir Richard Owen’s 
monograph, I venture to offer a few remarks upon the subject, by 
way of pointing out the mistake. A detailed description of the 
interesting bone in question may also be acceptable, since Prof. 
Cope’s materials appear to have been less complete and satisfactory 
than those now afforded by the fossils from the English Jurassic. 
The first specimen of interest in this connection is a small slab of 
Lias from Lyme Regis, exhibiting a number of dislocated cranial 
bones, which Mr. William Davies long ago recognized as belonging 
to Ichthyosaurus, but which do not appear, hitherto, to have been 
submitted to so careful a study as their admirable state of preserva- 
tion renders desirable. In the middle of the fossil, the basioccipital, 
basisphenoid, and presphenoid are arranged in irregular series, with 
their upper aspect exposed ; in front are the remains of the supra- 
occipital and parietals ; and on either side are scattered a number of 
1 'T. H. Huxley, ‘ Anatomy of Vertebrated Animals,’ 1871, p. 211. 
2 B. D. Cope, “ On the Cranium of the Ichthyopterygia,” Proc. Amer. Assoc. 
Adv. Sci. vol. xix. (1870), pp 200-203. (For this reference I am indebted to 
the kindness of Mr. J. W. Hulke, F.R.S.) 
3 R. Owen, “ Fossil Reptilia of the Liassic Formations.—IIT.” (Mon. Pal, 
Soc. 1881), p. 96; also, ‘ History of British Fossil Reptiles, vol. ii. (1884), 
p. 54. 
