CLASSIFICATION OF DEVONIAN FISHES 431 
distinct, parietals, and equally distinct frontals. In short, they con- 
stitute a family of Ganoids, which I propose to call GLYPTODIPTERINI, 
and which may again be subdivided into two groups, or sub- 
families, the one, which might be called the rhombiferous Glypto- 
dipterini, containing the genera Glyptolemus, Glyplopomus, and 
Gyroptychius, with diphycercal tails, and for the most part rhom- 
boidal scales ; and the other, which might be termed the cycliferous 
Glyptodipterini, containing Holoptychius, Platygnathus, and Glyp- 
tolepis, with heterocercal tails and cycloid scales. 
Professor Pander has endeavoured to prove that the teeth known 
_ as Dendrodus belong to fishes of the genus Gyroptychius. The 
evidence brought forward in support of this view, however, appears 
to me to be hardly sufficient to demonstrate its accuracy ; though 
I think it extremely probable that the teeth and jaws, which have 
been referred to the genera Dendrodus, Cricodus, Lammnodus, 
Platygnathus, and Rhizodus, will turn out to belong to allies of 
Gyroptychius, or, in other words, to fishes belonging to the family 
of Glyptodipterini. And again I cannot adopt the family of 
“Dendrodonts” which Professor Pander has established for Gyro- 
ptychius, Cricodus, &c., partly because, as he defines it, it seems to 
me to separate naturally allied genera, and, still more, because the 
“dendrodont” character is quite as strongly marked in other fishes, 
é. &, Megalichthys, which certainly do not belong to the same family 
as Gyroptychius, though undoubtedly related to it. 
The resemblances which obtain between Gyroptychius, on the 
one hand, and Osteolepis, Diplopterus, &c., on the other, have been 
well pointed out by Professor Pander, whose Monograph upon the 
Saurodipterini is not less excellent than that already cited, though 
it should not be forgotten that Hugh Miller long ago published 
an excellent restoration of Osteolepis.' Diplopterus has, in fact, 
the elongated from, depressed head, forward orbits, long gape 
and conically tapering caudal end of the body, which characterize 
Glyptolemus. The pectoral fins are similarly, though not so acutely, 
lobate, and the lobate ventrals are situated far back, as in the 
1 See ‘*The Old Red Sandstone,” PI. iv. fig. 1, Osteolepes major. It appears from this 
figure that even the lobation of the pectoral fin had not escaped Hugh Miller, though he does 
not particularly refer to it in the text. Before Professor Pander’s work appeared in this 
country, I had obtained from Caithness, by the well directed activity of Mr. Peach and placed 
in the Museum of Practical Geology, a series of specimens illustrating all the chief structural 
characters of Osteolepis as detailed above. The lobate pectorals of Osteolepz's and Diploplerus 
are exhibited very well by specimens in the Iunterian and British Museum; the fact that 
“small ganoid scales are continued upon” the bases of the pectorals being noted in the 
description of No. 567 in the Catalogue of the former Museum. 
