354 RAMSAY H. TRAQUAIR ON THE 
In no specimen has any trace of vertebral bodies been observed, and the 
extraordinary distortions of form, so common in specimens of this genus, 
yield additional evidence that the vertebral axis was notochordal. 
Genus II. Benedenius, Traquair, 1878. 
Paleoniscus, P. J. Van Beneden, 1871. 
My distinguished friend, Professor Dr Konincxk of Liége, having come to 
entertain doubts as to the “ Palzoniscus de Denée” of Professor VAN BENEDEN* 
being really referable to that genus, did me some time ago the great honour 
of confiding to me for redescription the unique and valuable specimen of that 
remarkable fish from the Carboniferous Limestone of Denée in Belgium. As 
my detailed account of its structure has already appeared in the first part 
of Professor De Kownincx’s new great work on the Fauna of the Belgian Car- 
boniferous Limestone,t I shall here restrict myself to noting a few points 
concerning its generic peculiarities and its place in the system. 
Benedenius Denéensis, Van Bened. sp. (Plate IIT. fig. 17), has the body ovoid, 
with the dorsal and ventral lines pretty evenly arched, the caudal fin power- 
fully heterocercal and inequilobate. The dorsal fin, shaped much like that of 
Eurynotus, arises, however, as in Wardichthys, considerably behind the middle 
of the arch of the back; its base extends to the tail pedicle. The anal fin 
is triangular and acuminate, with a short base; the ventrals are placed rather 
far back ; the pectoral is not completely preserved, but appears rather delicate ; 
the fins are strongly fulcrated. The scales are of moderate size, and arranged 
in the usual oblique dorso-ventral bands, which, beneath the pectoral, turn 
forwards as in Mesolepis, Cheirodus, &c. Those of the flank are not much 
higher than broad, delicately striated with transverse and oblique ridges ; but 
as they all lie so very closely in position, and none are seen from the internal 
aspect, it is impossible to get a view of their entire contour or mode of articula- 
tion. A row of large and prominent median scales extends from the front of the 
dorsal fin to midway between that fin and the occiput; the belly between the 
ventrals and the lower extremity of the shoulder-girdle displays a series of pro- 
minent narrow plates, whose long axis are directed downwards and forwards. 
The shoulder-girdle is conformed as in Hurynotus. The suspensorium is nearly 
vertical, slightly inclining forwards ; the orbit is placed right over the middle of 
the jaw. The operculum is small and square shaped, the interoperculum is 
much larger and higher, and is followed by a series of branchiostegal rays. 
The outer aspect of the posterior part of the mandible displays a very peculiar 
* Bull. Ac. Roy. Belg. xxxi. 1871, pp. 512-515, plate iv. 
+ Op. cit. pp. 14-23, plate ii. 
