A NEW GENUS OF GANOID FISH. 477 



able to learn if the species was new, as the gentleman who has the charge of 

 that particular department was unfortunately absent in bad health. They ap- 

 peared, however, to resemble a species from Sierra Leone, unnamed in the col- 

 lection ; and the presence of the so-called pupse, is probably somewhat of a rarity, 

 at least none were noticed among the specimens exhibited in the cases. 



I am indebted to Mr R. F. Logan, Duddingston, who fortunately combines in 

 himself the entomologist and the artist, for the annexed very correct drawings of 

 these insects, which will, I hope, enable those more intimately acquainted with 

 the Termitidce to determine their species. 



A small and partially digested crustacean, of the prawn kind, was the only 

 other creature observed in the stomachs of these fishes. 



General Summary of the Genus Calaruoichthys, and its relation to the Genus Polypterus. 



Genus Calamoichthys. — Head, small, depressed above, somewhat oval in 

 shape (rounded and narrow in front, expands laterally behind orbits, and con - 

 tracts again at the back part towards neck); sub-operculum wanting (no small 

 plates below pre-operculum). 



Body, much elongated, anguiform (cylindrical for about half its length, then 

 becoming gradually more compressed laterally, and tapering very slightly towards 

 its caudal extremity). Caudal extremity, short, tapering rapidly. Caudal Jin, 

 rounded; homocercal in its general contour; fin-rays, hard. {Scales, osseous, 

 rhombic, sculptured; becoming somewhat larger in size as you proceed back- 

 wards along the body, and again smaller on the caudal extremity.) 



Fins, small : — Pectorals, obtusely lobate ; fin-rays, soft. Dorsal jinlets, nume- 

 rous, separate. A nal, in male, large ; in female, small; fin- rays, hard. Ventrals, 

 wanting. 



The last character is rather an important one, as this fish thus appears to be 

 the only living ganoid yet known which has no ventral fins. Van der Hoeven, 

 in his valuable " Handbook of Zoology," gives the presence of ventral fins as one 

 of the characters of his great Section III. of the Class Pisces, the Ganoidei, or, 

 as he terms them, the Ganolepidoti. He says they have " pectoral and ventral 

 fins, the ventrals placed behind the pectorals." While older naturalists, as Cuviee, 

 from the supposed constant presence of ventral fins, have placed the ganoids in 

 the Order of Malacopterygii abdominales. The discovery of this new fish will, 

 therefore, necessitate a change in this character of the whole section. 



In the Genus Polypterus (on the other hand), the Head is relatively larger 

 I with apparently little or no lateral expansion, and subsequent contraction 

 towards its neck) ; its gently swelling outlines gradually expand, and run back- 

 wards into the tapering outlines of the body. Sub-operculum present ; several 

 small plates below pre-operculum. 



Body, relatively much shorter, generally tapering gradually from behind the 



VOL. XXIV. PART II. 6 N 



