520 Reriews—J. W. Davis— Carboniferous Limestone Fishes. 
Monograph, 14 are founded on the spines of Hybodonts; 4 generic 
names denote various peculiar cranial bones and dermal plates, of 
which it is often difficult, if not impossible, in the present state of 
our knowledge, to determine the true anatomical relations; the other 
41 genera are founded on the various forms of teeth of the types of 
Orodus, Petalodus, Cochliodus, Psammodus, and Copodus. 
The author refers to the fact that in the Liassic formation the 
teeth of Hybodus have been found in such connexion with the 
dermal spines as to place their relation to each other beyond a doubt. 
Yet he observes, ‘‘The teeth and spines of Ctenacanthus have not been 
so found, but judging from analogy, it appears probable that the teeth 
of Cladodus may have been associated with the spines of Ctena- 
canthus. Except that the Cladodi are more formidable and that the 
coronal prominences are more prominent, they bear a close re- 
semblance to the teeth of Hybodus.” (p. 331.) 
Notwithstanding the large development and wide distribution of 
the Carboniferous Limestone Formation in the British Islands, the 
number of localities yielding fossil fish-remains is comparatively few. 
Of the ten localities tabulated (pp. 545-548), Armagh takes prece- 
dence of all the others for the richness of its ichthyic treasures, no 
fewer than 117 species having been obtained by Lord Enniskillen 
from this important locality. Probably the same careful investiga- 
tion of other less prolific localities might have produced an equally | 
rich harvest. From Hook Point only one species, Streblodus 
Hgertoni, seems to have been obtained. Bristol has 21 species to its 
credit; Oreton and Farlow in Shropshire, 15 species (chiefly ob- 
tained by Mr. Weaver Jones and Mr. Baugh) ; Richmond probably 
claims most of the 26 species attributed to Yorkshire, where the 
labours of the late Mr. Edward Wood, F.G.S., added so many new 
forms to the Mountain Limestone fauna. Derbyshire yields 13 
species; Kendal in Westmoreland, 5; the West of Scotland, 35 
species: Lowick, Northumberland, 11; and Tortworth, Gloucester- 
shire, which has yielded a single ichthyodorulite to the Earl of 
Ducie, in whose collection may also be seen the largest fish-spine 
from the Carboniferous Limestone, found near Bristol, 27 inches in 
length and stout in proportion (drawn natural size on pl. lxv.). 
It is interesting to observe that out of 163 species recorded by Mr. 
Davis, 117 have been obtained from one locality, viz. Armagh. 
In a work like the present, it seems very difficult to offer many 
remarks of a critical nature; we may perhaps be permitted, without 
undue severity, to suggest that, as a matter of utility, the coloration 
of the plates might have been, for the most part, omitted, as it 
seldom has any pretension to be a reproduction of the colour of the 
original matrix or fossil. The pieces of dermal and other bones 
represented upon pl. Ixii. are (for the most part) too fragmentary to 
assist us in arriving at their true nature. At a future time, no doubt, 
many of the species formed upon single specimens of teeth, or on 
fragmentary ones, will have to be eliminated. 
In his determinations and deductions, Mr. J. W. Davis has closely 
followed the lead of Prof. L. G. de Koninck as expressed in his 
