168 FOSSIL FISHES OF THE ENGLISH CHALK. 
the outer paired series; they are usually a little longer than wide, and in the 
specimen figured they are reduced in size behind. The teeth of the outer paired 
series are steepest at the external face, and descend to a wide cingulum within. 
This cingulum is especially wide in a smaller (younger) specimen of the vomerine 
dentition from Guildford (B. M. no. 49802), and the outer lateral teeth are 
slightly larger than the median teeth. A still smaller specimen (Pl. XXXV, 
fig. 7), probably of the same species, shows only the three principal rows of 
teeth, with the beginning of an inner paired series of small teeth behind. Here 
the teeth exhibit a coarsely punctate surface, as if their external layer had been 
removed. 
In a supposed fragment of the splenial dentition of the same species 
(Pl. XXXV, fig. 6), the apex of each tooth in the principal series projects 
forward and is continued behind into a short keel. There are a few relatively 
small mammilliform teeth on each side. 
Remarks.—Some oval Gyrodus-like teeth figured by Dixon (op. cit., pl. xxxu,* 
fig. 6) seem to resemble very closely those just described, but their ornament is 
represented as consisting of radiating lines of ill-defined tubercles. They are 
named Gyrodus divoni by W. A. Ooster, Protozoe Helvetica, vol. 11, 1870, p. 46. 
Horizons and Localities—Turonian zones: neighbourhood of Lewes. Zone 
of Terebratulina gracilis: Warlingham, Surrey. Also Chalk near Guildford. 
2. Pyenodus scrobiculatus, Reuss. 
1845. Pycnodus scrobiculatus, A. E. Reuss, Verstein. bohm. Kreideform., pt. i, p. 10, pl. iv, figs. 15—25. 
1875. Pyenodus scrobiculatus, H. B. Geinitz, Paleontogr., vol. xx, pt. 1, p. 301, pl. lxv, figs. 22—32. 
1893. Pycnodus scrobiculatus, A. 8. Woodward, Geol. Mag. [3], vol. x, p. 492, pl. xvii, fig. 2. 
1895. Pyenodus scrobiculatus, A. S. Woodward, Catal. Foss. Fishes B. M., pt. iii, p. 281. 
T'ype.—Teeth from the Cenomanian of Bohemia. 
Specific Chavacters.—Teeth tumid and much resembling those named Giyrodus (2) 
cretaceus, Closely arranged in three longitudinal series on a narrow vomer. 
Median and lateral vomerine teeth about equal in size, the former with a shallow 
pit at the apex, the latter truncated at their outer border. 
Description of Specimens.—The examples of this species are always very 
small, and may belong to an immature fish. The specimen described and figured 
loc. cit. 1893 exhibits well the shallow pit in the median teeth. All the teeth 
are longer than wide. 
Horizon and Locality.—Probably zone of Holaster subglobosus : Charing, Kent. 
3. Phacodus punctatus, Dixon. Plate XXXIV, figs. 7, 8. 
1850. Phacodus punctatus, F. Dixon, Geol. Sussex, Po orl, pl. xxx, te. 16: 
