of Polypterus, from West Africa. 243 
row, which are separate, sharp-pointed, and nearly even, 
Behind these is a broad band en velours, extending backward 
beyond the angles of the mouth. The vomer expands at its 
anterior extremity into a circle which fills entirely the space 
between the bands already mentioned. This circular part, 
the remainder of the vomer, and the anterior portion of the 
-sphenoid are also studded with thickly set teeth. The pala- 
tine bones and all the space between the maxillary bands and 
the sphenoid are furnished in the same manner. The whole 
upper surface of the mouth, therefore, is covered with teeth 
en velours. The lower jaw has a row of separate, sharp- 
pointed teeth, similar to those in the upper jaw. Behind 
these is a band of fine teeth, which however does not extend 
to the angle of the mouth. "The tongue is broad, free, and 
“smooth. 
The pectora! fins arise beneath the posterior portion of the 
operculum. ‘They are supported as in other species of the 
genus, upon an arm-like process or base. This is half an 
inch in height and is rounded on its posterior margin ; it is 
covered externally with minute plates similar to those of the 
ody. These minute plates overlap the borders so as to 
appear on the edge of the inner surface, but the greater por- 
tion of this surface consists of smooth skin unarmed. e 
naked space thus left is bounded posteriorly by a curved row 
of very small plates or scales at the base of the pectoral rays. 
The plates are rounded at the base, with the summit some- 
what truncated and armed with one to four slender, acute, 
uncinate spines or teeth. The surface of each plate is ridged 
like the shagreened plates of the head. Posterior to this 
row, on the membrane connecting the pectoral rays are 
placed many narrow scales which are furnished also with 
slender teeth. (Pl. 6, fig. 6.) These scales are not imbri- 
cate, each one being attached separately ; they do not extend 
over more than about half the height of the fin and half its 
length. They are not seen on the external surface, but in 
their place we find many enamelled ridges or tubercles not 
