Morgan Expeditions. 126 
is readily distinguished from P. sulcata, by the regular 
curvature of the surface from the anterior to the posterior 
end, and by the absence of a sinus. 
From the Devonian sandstone of Ereré, Prov. of Para, 
Brazil; associated with Spirifera Pedroana, ete. 
Genus TENTACULITES, Schlotheim. 
Tentaculites Eldredgianus, sp. nov. 
Shell smaii, rather long, straight, circular in cross-section, at least 1™™ 
in diameter at the larger end, and tapering very gradually to an acute 
point. Length of the most perfect specimen, a fragment, about 16™™. 
Annulations narrow, quite prominent, and angular or slightly rounded 
on the summit; the interspaces are generally about twice as wide as 
the annulations, theugh they vary somewhat in width, and are flattened 
or a little rounded in the bottom; they are ornamented by fine annular 
raised lines, of which there are about four or five in each interspace, 
near the larger end of the specimen. The annulations decrease in size, 
but become more numerous toward the apex. There are about 5 to 7 
in the space of 3™™ near the large end. 
The specimens of this species, so far obtained, are from 
the sandstone, in which they exist as moulds of the exterior 
surface, generally filled up with clay or sandy material. 
The moulds usually preserve the impression of the annu- 
lations very sharply; the annular raised lines, however, 
are seldom preserved. The casts formed by the filling up 
of the moulds are never exact copies, but in them the an- 
nulations are almost always low and rounded. The full 
length is not preserved in any of the specimens obtained, 
but it was probably not much greater than 16°". Although 
the distance between the annulations varies, the variation 
is never very great, and is generally regular through the 
same specimen, the interspaces becoming gradually narrower 
toward the apex. 
From the sandstone of the Devonian age, Ereré, Proy. 
of Para, Brazil; associated with Spirifera Pedroana, etc. 
