125 Morgan Expeditions. 
which is crenulated in that genus. Only a few specimens 
have been obtained. 
From the Devonian sandstone of Ereré, Prov. of Para, 
Brazil; associated with Streptorhynchus Agassizii, ete. 
Paleeaneilo? simplex, sp. nov. 
Shell of medium size, elongate, quite regularly sub-elliptical in outline 
and of moderate convexity; height about two-thirds the length. Anterior 
margin not quite as high as the posterior; both anterior and posterior 
margins regularly and quite strongly rounded, and passing gradually into 
the ventral margin, which is regularly and moderately rounded. The 
dorsal margin is nearly straight and extends directly backwards from the 
beak; its length is less than one-half that of the shell. Beaks situated 
at about one-third the length of the shell from the anterior end, quite 
small, rather strongly incurved to the plane of the hinge, and slightly 
elevated above the hinge margin, with the apices acute. The point of 
greatest convexity of the valves is just above the middle. The curvature 
of the surface from the ventral margin to the beaks is moderate and 
nearly regular, growing gradually stronger, however, toward the beaks. 
The curvature along the antero-posterior diameter is quite moderate and 
regular, the slopes toward the anterior and posterior margins from the 
middle being sub-equal. Toward the dorsal margin the slope is moderate 
posteriorly, but grows gradually stronger as the beaks are approached, 
just behind which it is very abrupt. Immediately in front of the beaks 
the surface is slightly concave. Surface markings unknown; the surface 
of the internal moulds is quite smooth. Length, 16™™; height, 12™™; 
depth of single valve, 3™™. 
The above description of this form was made from a 
single, very perfect specimen, an internal mould of the 
left valve, in which, however, the characters of the hinge 
are not preserved. The generic relations of the species 
are thus rendered doubtful; but it agrees externally with 
Prof. Hall’s genus Paleanetlo in which we place it pro- 
visionally. Besides the single specimen just mentioned, 
there are four or five other specimens of lamellibranchs 
from Ereré, which apparently belong to this same species. 
In them the beak is sometimes more acute, and the curva- 
ture of the surface varies slightly. In all the other char- 
acters they agree quite perfectly. This form of Paleaneilo 
