438 On the Fossil Fishes of the Carboniferous Limestone Series of Great Britain. 
of the posterior margin it may perhaps be inferred with reasonable probability, 
that a process of growth increasing the size of the tooth along its broad posterior 
and inside margin may be indicated ; though there are no lines or ridges indicating” 
growth as in Deltodus sublevis, this method agrees with the other species in its 
application. The specimens found at Bristol are smaller than those from Oreton, but 
there does not appear to be any distinguishing feature which would lead to the 
supposition that there is any specific difference between them. 
Sandalodus morristi was found associated with several other species of fish- 
remains in the Mountain Limestone at Oreton, in Shropshire; amongst others. 
were Orodus ramosus and species of Helodus, Cochliodus, Cladodus, Psammodus 
and Ctenacanthus. It is figured without name or description in the ‘ Quar. Journ. 
Geol. Soc.” Vol. XVIIL., pl. iti., figs. 2a, 2b, 2c, by Prof. J. Morris, and Mr. Geo. 
E. Roberts. 
The upper teeth of this species bear a superficial resemblance to an American 
species, Deliodus grandis, Newberry and Worthen, from the Keokuk Limestone 
of Illinois. It may, however, be easily distinguished by its generally rounded and 
more circular form, and the absence of a deep sulcus extending longitudinally 
parallel with the lateral ridge: in D. grandis the broader end of this sulcus is 
strongly elevated. 
I have taken the liberty of appending the name of Prof. Morris to this species, 
he having first introduced it to notice in the paper cited above in 1862. Hitherto. 
it is the only described species of this genus from British strata. 
Formation and locality: Mountain Limestone, Oreton, Salop; Black Rock, Bristol. 
Ex coll. Earl_of Enniskillen ; Dr. Grenfell, and Bristol Museum. 
Genus—Psephodus, Agass., MSS. 
Cochliodus— L. Agassiz, 1838. “Rech. Poiss. Foss.,” Vol. III., p. 174, indet. 
Helodus (partin)— __,, 1838. AL cr . 5 WO, Te dle 
Psephodus— ms 1859. “MSS. Enniskillen Coll.” 
Aspidodus— Newberry and Worthen, 1866. “ Geol. Sury. Illinois,” Vol. I., p. 92. 
Palatal teeth varying greatly in size and form; outside sub-rhomboidal inclined 
to pentagonal or oblong; surface, broadly convex with a decided obliquely 
diagonal torsion. Diameter varies from 2°1 by 1:5 inches, to others which are 
‘5 by -2 inch only. Anterior margin more or less convoluted, comparatively 
broad ; surface expands posteriorly to nearly double the width of the anterior 
margin. Posterior margin, rotund. Sides, straight where the teeth have been in 
juxtaposition ; margins all vertically plicated. Coronal surface thickly coated 
with enamel or dentine, porous or pustulate. Base, thick and strong, conforms to 
surface of crown but is considerably constricted in area. 
