_ THE 
GHOLOGICAL MAGAZINE. 
No. X.—APRIL 1865. 
ORIGINAL ARTICLES. 
——_}——_ 
I. Description oF PorTIONS OF JAWS OF A LARGE EXTINCT 
Fisa (Srerzopus Metirensis, Ow.), PROBABLY A ‘CyYCLOID’ 
witH ‘Savuroip DENTITION,’ FROM THE ‘MIDDLE BrpDs OF THE 
Mattese Miocene.’ With a Woodcut. 
By Prof. Owrn, F.R.S. 
SEN S indicative of large ‘cycloid’ Fishes, with 
teeth of ‘sauroid’ character, have been obtained from the 
‘Upper Chalk’ of England. Toa species of this kind, with 
large circular scales covered with minute asperities visible by 
the aid of a pocket-lens, Agassiz assigned the generic name 
Pachyrhizodus, in reference to the thickness of the base of the 
anchylosed teeth. 
A portion of upper and lower jaws of a Fish of this cha- 
racter has been submitted to me, for examination, by A. Leith 
Adams, M.D. The specimen forms part of a larger proportion 
of the skeleton of the same fish, from the middle beds of the 
Maltese Miocene, now in the Museum of the Malta Uni- 
versity. 
The teeth, with crowns from 7 to 8 lines in length, are conical, 
slightly curved toward the inner(?) side of the jaw: sharp-pointed, 
with a full elliptical, in some almost circular, transverse section. 
The surface of the crown is smooth ; the hard polished enamel is 
most conspicuous near the apex; a very thin, less bright glazing is 
continued to the base of the crown, which rather suddenly swells 
into the part confluent with the substance of the jaw. At this part 
the tooth is solid and compact: the diameter averages 3} lines by 
3 lines. In a specimen of Pachyrhizodus basalis, Dixon,* the base 
* The Geology and Fossils of the Tertiary and Cretaceous Formations of Sussex, 
4to. 1850, p. 347, pl. 34, figs. 2, 10, 10*. 
VOL. II.—NO. X. L 
