128 
PALEONTOLOGY OF NEW YORK. 
have a forward bend near the axial furrows and a slightly retral curve over 
the median line. 
PleurcB evenly convex and bearing from six to eight annulations, each of 
which is grooved by a finely impressed line. All the annulations become 
extinct upon reaching the border. 
Surface Ornamentation. Upon the cephalon and thorax the test is covered 
with faint, nearly obsolete pustules or granulations, which seem to be want¬ 
ing upon the pygidium, except at the posterior edges of the axial annula¬ 
tions. The last four or five segments of the thorax each bear a strong 
tubercle in the axial line, as in Proetus Rowi. A faint axial tubercle is also 
visible upon the occipital ring. 
Dimensions. An entire individual of normal proportions measures ; 
Body. Cephalon. Thorax. Pygidium. 
Length_ 37 mm. 14 mm. 13 mm. 10 mm. 
Width_ 26 mm. 26 mm. 20 mm. 19 mm. 
Observations. The Proetus Davenportensis of Barris, appears to be identical 
with Shumard’s type, and the description here given is from Mr. Barris’ original 
specimens, which he has kindly loaned for the purpose. 
Proetus Prouti may be regarded as a western representative of the type of 
Proetus, exemplified by the New York species, P. angustifrons, P. clarus and P. 
Rowi. With the last named species it has many points of close similarity, both 
in general contour and in details. It will be found, however, to differ in the 
following particulars, which,taken together, prove of specific value; the cephalic 
border is broader and more conspicuously grooved; the genal spines very much 
longer; the axis, both upon the thorax and pygidium, narrower; the pygidium 
more evenly convex, and with a more conspicuous border. 
Distribution. Hamilton group. In the fawn-colored limestone, near Daven¬ 
port, Iowa. 
