OF DENISON UNIVERSITY 
29 
Phillipsia shumardi. Herrick. 
(Plate II, Fig. 22. ) 
Proetus missouriensis, Shumard. Geol. Missouri. 
Abundant in the freestone of middle Waverly. See Bui. Den. 
Univ. Vol. II, Part I, page 69. 
Phillipsia praeoursor, sp. n. 
(Plate XII, Fig. I.) 
Closely related with P. shumardi. Her. 
Head shield parabolic in outline, axial portion very high, rapidly 
curved, highest portion near the centre of the glabella. Glabella 
nearly twice as long as wide, anteriorly forming a high, rounded, fine- 
ly striate ridge, separated /rom the axial elevated portion by a deep 
but narrow sulcus; postero-lateral lobes small, oblique, well defined 
by the arched grooves which reach the cervical groove or nearly so, 
and separated from each odier by an interval equal to their own width; 
there is but a single pair of secondary on lateral lobes with a pretty 
well defined sulcus lying well back of the centre ; palbebral lobes 
large, quadrate ; cervical suture deep and wide, cervical segment 
rather large. The cheeks are bordered by a triangularly elevated mar- 
gin and a rather deep groove and project backward into short, acute 
spines. None of our specimens show the fixed cheeks and the figure 
of the head is imperfect in this respect, but bears a strong resemblance 
to P. gemmulifera. Pigidium nearly semicular, moderately elevated, 
about times as wide as long, the axial portion is high, tumidly 
conical, and obtuse, marginal sulci rather deep ; axis composed of nine 
(ten) segments separated by deep grooves, pleural portions rather reg- 
ularly convex, with about seven apparent ribs which are elevated and 
pustulose dorsally and bifurcate near the margin ; margin convex, sep- 
arated by a shallow groove. All of the annuli as well as the median 
parts of the gebella, are covered with well defined pustules. Length 
of glabella 14 mm ; width 7 mm. or more; length of pigidium ii rpm; 
width 17 mm. 
This form is obviously very nearly allied to P. elliptica from the 
