Carbo)iiferou^ Trilobltcs. 81. 



with 8 or 9 riiiiis, tapering to the posterior end, wliicli is somewhat abruptly 

 rounded otT, one tenth of an incli from the extremity of tlie pygidium ; 

 lateral lobes with 8 or 9 segments, becoming obscure posteiiorly. Border 

 about one-sixteenth of an inch broad, maiked on the under side by nine 

 rigid, sharply impressed stride. Exterior crust verj^ finely and obscurely 

 granulated. 



Comparisons. — According to Winch ell, this species seems to 

 approach nearer to Proetus articulatus Hall (15th Rep. JN". Y. 

 State Cab. Nat. Hist., p. 107), from the Chemung group, Lick- 

 ing Co., Ohio ; but is destitute of the anterior and middle fur- 

 rows of the glabella. It differs from Proetus {PMUipsia ?) ellip- 

 ticus, Meek and Wortheii, from the Waverly series, in the charac- 

 ters of the cephalic border, in the absence of glabella furrows, 

 and in the border of thepygidium. 



Geological position and locality : — Waverl}^ series, Hickman 

 Co., Tennessee. 



FKOETUS TKINUCLEATUS, Herrick. 



Plate 2, Figs. 7. 8, 9, 



PMUipsia trinudeata, Herrick, 1887, Bull. Lab. Denison Univ., Vol. II, p. 



64, pi. 1, figs. 23 and 23 a, c, e, 7i ; pi. 2, fig. 32 ; pi. 3, fig. 21. 



The characteristic features of this species are drawn from the glabella : 

 according to the author, "it is considerablj^ longer than wide, and quite 

 convex, the greater height being posterior to the middle. Anterior de- 

 pressed margin rather narrow in front, expanded laterally ; sides nearly 

 straight or somewhat concave near the eyes ; postero-lateral lobes very 

 sharply defined, conical, oblique, with a second smaller pair in front of 

 them, and a very faintly outlined second pair still farther forward ; between 

 the postero-lateral lobes a sharply defined, prominent, median elevation, 

 almost as large as the others ; cervical segment convex, high, often with a 

 single median tubercle. The surface of the glabella is minutely ornamented 

 and on either side in front of the eyes is an oval pit which has been thought 

 by some to represent the insertion of the antennae or organs of sense." 



' ' The ej^es are large and supported by a prominent j)alpebral lobe. A sin- 

 gle movable cheek has been found ; the margin is obliquely inclined, form- 

 ing a prominent angle at its union with the face ; middle of cheek depressed 

 and marked with am impressed line ; cheek produced i to a spine as long as 

 the whole remainder of the cheek ; length of cheek, .77 (the spine, .35); 

 length of ej^e, .11. Pj^gidia are not rare and are very convex, the median 

 lobe especially being convex from side to side, and particularly prominent 

 posteriorly. The median lobe occupies \ or less the width of the p3^gidium 

 proximally and tapers gradually, forming a portion of a regular truncate 



