114 Dr. R. H. Traquair on the Anatomy of Calamoichthys. 
In the genus Polypterus, on the other hand, the head is rela- 
tively larger (with apparently little or no lateral expansion and 
subsequent contraction towards the neck) ; its gently swelling 
outlines gradually expand and run backwards into those of the 
body. Suboperculum present; several small plates below pre- 
operculum. Body relatively much shorter, generally tapering 
gradually from behind region of pectoral fins, and becoming 
more compressed laterally towards its caudal extremity. Caudal 
extremity longer. Scales generally smooth (?). Fins larger ; 
pectorals, fin-rays osseous; anal apparently alike in size in 
male and female; ventrals present. 
The genus Calamoichthys agrees, however, with Polypterus in 
the general character of its numerous dorsal finlets ; lobate pec- 
torals, two nasal cirri, a spiracle on each side of the head above, 
and a large flat branchiostegous ray, or jugular plate, on each 
side of the mesian line below; and also in the hard, osseous, rhom- 
boidal-shaped ganoid scales, arranged in rows running obliquely 
backwards, and in the tapering caudal extremity of the body. 
The new genus belongs, therefore, to the same family as Po- 
lypterus, and would accordingly fall to be placed next to it in 
the family of the Polypterini. 
Family Polypterini. 
I. Genus Potyprerus. 
II. Genus CatamorcatuHys. 
1. Species C. calabaricus. 
(The specimens described measured from 8 to nearly 13 inches 
in length.) 
Hab. Old Calabar River, and the Camaroons, West Africa. 
(A female sent by Mr. G. W. Mylne from the latter locality, 
and recently received by Dr. Smith, was also exhibited.) 
On dissecting those specimens of Calamoichthys entrusted to 
the author by Dr. Smith, the greatest similarity was found to 
exist between their internal organization and that of Polypterus, 
the chief differences bemg dependent on the great elongation of 
the body of the former fish, while the abdominal cavity extends 
proportionately still further back towards the caudal extremity 
than is the case even in the genus last mentioned. 
The vertebre resemble in construction exactly those of Poly- 
pterus, but are very much increased in number, amounting, in the 
specimen which was used for the preparation of the skeleton, to 
110, the first of which has no body, consisting merely of neura- 
pophyses, spinous process, and a pair of ribs. These latter form 
