OF DENISON UNIVKRSITY 20 



Phillipsia shumardi. Herritk. 

 (Plate II, Fig. 22.) 



Proetus missouriensis, Shumard. CJeol. ?\Iissouii. 



Abundant in the freestone of middle Wavcrlv. Sec Ilul. Den. 

 Univ. Vol. II, Part I, page 69. 



Phill7})sia prarcHJ'.sfjr, 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 other by an interval equal to their own width; 

 there is but a single pair of secondary on lateral lobes with a pretty 

 Avell 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 i^ times as wide as long, the axial portion is high, tumidly 

 conical, and obtuse, marginal sulci rather deep ; axis composed of nine 

 (ten) segments sei)arated by deej) grooves, pleural portions rather reg- 

 ularly convex, with about seven api)arent 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 i 1 mm; 

 width 17 mm. 



This form is obviously very nearly allied to P. elliptica from the 



