new Fishes from the Nile. 445 
Siluride. 
PHYSAILIA, gen. nov. 
Differing from Azlia, Gray, in the free air-bladder and the 
absence of vomerine teeth, from Parailia, Blgr., in the presence 
of a small adipose fin. 
Physailia pellucida. 
Depth of body 4 to 44 times in total length, length of head 
6 to 64 times. Diameter of eye about 3 times in length of 
head; nasal and maxillary barbels # to 4 total length, 
reaching extremity of pectoral fin or a little beyond; man- 
dibular barbels 4 to 2 total length. Pectoral as long as head, 
the spine serrated on the inner side. Anal 65-72, narrowly 
separated from the caudal, which is deeply forked. Colour- 
less, translucent in life. 
Total length 93 millim. 
Numerous specimens from Omdurman. 
Ailia somalensis, Vincig., probably belongs to the same 
genus, but it differs in the longer barbels and the pectoral 
spine is described as non-serrated. 
Galaxiide. 
CROMERIA, gen. nov. 
Body elongate, cobitiform, compressed, naked. Mouth 
small and inferior, toothless; gill-openings narrow, lateral. 
Ventrals midway between head and caudal; dorsal and anal 
short, the former opposite to the space between the latter and 
the ventrals. Air-bladder slender, elongate, extending along 
the whole precaudal part of the body. Vertebre 80+15. 
This remarkable new genus, which I take the liberty of 
dedicating to Lord Cromer, appears to be most nearly related 
to Galaxias, with which it agrees in the general structure of 
the vertebral column, the position of the fins, the absence of 
the mesocoracoid bone, and the naked skin. It differs widely 
in the small edentulous mouth and the narrow gill-openings. 
Cromeria nilotica. 
Depth of body 8 times in total length, length of head 6 
times. Snout rounded, projecting strongly beyond the 
mouth ; diameter of eye about 5 times in length of head. 
Dorsal and anal with 8 rays, 5 of which are branched. 
Caudal deeply emarginate. Colourless, except a bright 
