PALMOZOIC ROCKS IN CANADA AND SCOTLAND. 383 
arched and carrying ten minute teeth, of which the first two are 
pointed and divergent, the others rounded. Length 3 line. 
This species closely resembles A. pectinatus from the Cincinnati 
formation, but it is not so elongated and has fewer denticulations. 
Niagara formation. 
LuUMBRICONEREITES BASALIS, Hinde. (Pl. XIX. fig. 22.) 
Jaw with a long, narrow, curved ridge, supported on a wide 
triangular basal flange; the first tooth is long and nearly horizontal, 
and apparently forms the commencement of the ridge; on the summit 
of the ridge there are seventeen, blunted, roughly triangular denti- 
culations unequal in size. Length 13 line; width, including the 
flange, 2? line. 
Not uncommon, though perfect specimens are rarely met with. 
Clinton formation. 
LUMBRICONEREITES TRIANGULARIS, Hinde. (Pl. XX. fig. 4.) 
Jaw consisting of a flattened triangular basal plate with a very 
narrow vertical ridge; at the anterior end of the basal plate there 
are two incurved blunted teeth, whilst the ridge supports a series of 
eighteen blunted rounded teeth. Length 13 line, width 3 line. 
This species is closely related to L. dactylodus, but differs there- 
from in the angular outline of the front basal flange. 
Clinton formation. 
LUMBRICONEREITES ARMATUS, Hinde. (PI. XX. fig. 6.) 
Jaw consisting of a very narrow, vertical, slightly curved ridge, 
supported by a very wide, somewhat concave, horizontal basal flange, 
having in front a very prominent claw-shaped tooth, which is nearly 
in the same plane with the flange itself. On the vertical ridge there 
are nine sharp-pointed teeth, obliquely directed towards the posterior 
end of the jaw. Length 12 line, width 2 line. 
' I have only met with a single example of this clearly marked 
species. 
Clinton formation. 
STAUROCEPHALITES, Hinde, 
Jaws of more or less elongated, compressed, denticulate plates, 
resembling those of the existing genus Staurocephalus, Grube. Of 
this 1 have met with only one species. 
STAUROCEPHALITES NIAGARENSIS, Hinde. (Pl. XX. fig. 1.) 
Jaw oblong, the front border slightly curved and extending 
obliquely downwards, the posterior end rounded; on the upper edge 
of the plate is a series of sixteen very minute pointed teeth, of which 
the first is slightly larger than the others, and all are uniformly di- 
rected backwards. Length 3 line, about 4 line wide. 
This minute jaw is very abundant, but appears to be restricted to 
the dark shales of the Niagara formation. 
Q.J.G.8. No. 139. 25 
