ove Reviews—British Museum Catalogues— 
nodus, Thrinacodus, Lophacanthus, Anodontacanthus, and Didymodus. 
Diplodus, however, is provisionally retained for the teeth not 
correlated with spines. : ; 
Pleuracanthus decheni, a small species from the Lower Permian of 
Rhenish Prussia and elsewhere, has been long and is best known by 
numerous specimens in fairly complete preservation. With the 
exception of P. Gaudryi and P. (Didymodus) texensis, the other species 
are only known by teeth and the cephalic spines, the latter being 
placed on the head in advance of a small fin. Teeth and spines in- 
dicate that some species or individuals attained a large size. The 
remarkable, but imperfectly known Chondrenchelys, discovered by 
Dr. Traquair in the Lower Carboniferous rocks of Hskdale, is 
provisionally placed in this family on account of the resemblance 
to Pleuracanthus of the axial skeleton, the similarity of the form 
of the body and the presence of a long dorsal fin, but it 
has no cephalic spine. The Crapopontipm are “an indefinable 
family, apparently closely allied to the Pleuracanthide.” Dr. Tra- 
quair has discovered the pectoral fins of the type genus Cladodus, 
and states that they possess the characteristic structure of the order. 
But with this exception, all the species of the family are only known 
by detached teeth, no spines being assigned to the group. Six 
genera are noticed, three being American, but of these there are no 
specimens in the collection. Phabodus is a Devonian genus from 
Jowa. The other genera only occur in rocks of Carboniferous age. 
We next come to the order Sriacutt, andthe suborder Tectospoudyli, 
comprising twelve families, the first being the Sprnactp#, and the 
last the TRyconipm. ‘The first family, Spinacide, contains fossil 
representatives of the existing genera Centrina, Acanthias, Centro- 
phorus, Spinax, and Scymnus, hitherto classed with the Sharks. The 
fossil species of Acanthias and Centrophorus are from the Upper 
Cretaceous of Mount Lebanon, Syria. 
The Prratopontip# follow next, with nine genera. “The genus 
Janassa affords the most complete insight into the characters 
of this family;” the dentition of one species (J. bituminosa) from 
the Permian having been found in natural apposition. The other 
genera being only known by detached teeth and such fragmentary 
portions. A new genus and species, Mesolophodus problematicus ; 
and two species of Petalodus (P. flabellula and P. Davisii) are here 
first described. With the exception of the Permian Janassa bituminosa, 
all the other species are from Carboniferous rocks. The Squarinips 
have one genus, Squatina, and five species, two being Kimmeridgian 
and three Cretaceous. One new species (S. crassidens) from Mount 
Lebanon is described. 
To the Pristipa a new genus and species (Sclerorhynchus atavus) 
is added, founded on an imperfect rostrum, also from Mount Lebanon. 
‘ From this formation and locality the Museum possesses a large series of fish and 
other remains, remarkable alike for the numbers of genera, species, and of individuals 
represented, and also the beautiful state of their preservation. The collection 
contains many of the types of this subclass and also of the Ganoid and Teleostean 
fishes, described from this locality. 
