Prob. 



770 



part of head, with glabellar furrows ; 14, entire head, some fur 

 rows ; 15, enlarged twice^ tail of small individual ; 17, ditto 

 showing internal surface and doublure ; 20, profile view of 15 

 plate 23, fig. 30, nearly entire trilobite; 31, tail of a very large 

 specimen. The head is covered with low pimples (tubercles) 

 each ring of the chest and body is covered with granules, some 

 times as if in two rows. Whole trilobites are rarely found 

 and their crusts were so thin and tender that they were easily 

 torn away ; the movable cheeks also parted from the head 

 after death, so that only one perfect specimen was found by 

 Hall in several hundreds collected. The species scarcely varies 

 at all, and is quite distinguishable from P, curmmarginatus 

 which looks like it. It has been collected at a great many 

 places in New York from the Hamilton shales^ and lully lime- 

 stone leds, VIII c^ d. — In Pennsylvania, Perry Co., one col- 

 lected by Clay pole, at Burnett's mills (spec. 5-67) from Hamil- 

 ton upper shales, VIII c ; and six others at Slipping Rocks, 

 west of Mexico P. O. (spec. 40-6.-30,-55).— From Marcellus 

 limestone^ VIII a. — Possibly spec. 12584 (151-3) found one 

 mile northeast of Bridgeport, in Marcelhts. Villa ? c, f. 



Proetus parviusculus, Hall, Pamphl. 1866, Cincin. group, 



/5 20th and 24th reports N. Y. State cabinet. 

 Pal. Ohio, Vol. 2, 1875, page 109, plate 4, 

 fig. 18, enlarged four lengths, type speci- 

 \i men; surface smooth or very finely gran- 

 « ulose ; unlike all other American species 

 .1 of trilobite; differs from the the Bohe- 

 mian P, sGulptus^ Barrande, by having one more thoracic seg- 

 ment, 10 (P. So, has 9) ; differs strongly from Meek's P. spur- 

 locU, Pal. Ohio, I, p. 161, pi. 14, fig. 12. /// 5. 



Proetus planimarg^inatus. Meek. Proc. Acad. J^at Sci., 



VIHa 



Pal. 



s . 



1871. Pal. Ohio, Vol.1, 1873, 

 page 233 [? ] plate 23, fig. 3 a, 

 d, side, and top views of cast 

 of tail (pygidium) from upper 

 beds of Corniferoiis limestone 

 in Lucas Co., O. General out- 

 line like P. haldemani, Hall, 

 ;<yiii of the Hamilton strata^ but 



