Carhonifiirous Trilobitei>. 97 



American Museum of Natural History A'ew York, and from 

 Columbia College, also in the collection of Prof. J. J. bteven- 

 son, of }\(i\w York University. 



GKIFFITHIDES SCITULA, Meek untl Wortlien. 



Plate III, Figs. 11, 12, & 13. 



PhlWps'a (Griffithides) scltula, Meek aud Wortben, 1865 ; Proc. Acad. Nat. 



Sci. Phila.. p. 270. 

 PhWpsia ( Griffithides) scltula, JMeck and Wi.itlien, 1873 ; Paktoiit. Illinois, 



Vol. V, p. 612, pi. 32, tig. 3. 

 PhlWpsia sctuld. Meek, 1872; U. S. Geol. Sur. Neb., etc., p. 238, pi. 6, 



tig. 9. 

 Phillips: a scitula, Herrick, 1887; Bull. Sci. Lab. Denison Univ., Vol.11, 



p. 62. 



Tbe original description of tbis species given by Messrs. Meek and Wor- 

 tben in tbe Palaeontology of Illiuois, Vol V, p. 612, is as follows: — 



'• Small, entire outline nearly elliptic. Cepbalic sbield semi-elliptic, 

 very convex, about one-tbird its breadtb wider tban long, rounded anterior- 

 ly, aud nearly straigbt bebmd, witb posterior lateral angles produced back- 

 wards into ratber stout, carinated pointed spines, wbicb extend as far back 

 as tbe tiftb tboracic segment. Glabella broadly rounded and sloping in 

 trout, wbere it is witbout a projecting marginal rim ; distmctly contracted 

 posteriorly, in wbicb region it is most elevated ; separated from tbe cbeeks 

 on eacb side by its mucb greater convexity, and a sballow lurrow, wbicb 

 becomes obsolete around tbe front ; posterior lateial lobes comparatively 

 large subtrigoual, very oblique, depressed, and isolated by tbe strongly de 

 tiued lateral furrows in front of tbem being so very oblique, and produced 

 as to iuteisect tbe neck-furrow ; nudway between tliese two lobes tbere is a 

 a more prominent mesial node, isolated by an accessory furrow passing 

 across tbe front of it. so as to cut it oif, as it were, from tbe narrow pos- 

 terior central part of tbe glabella ; second and tbird lateral lobes very small, 

 transverse, and obscurely defined by sbort, nearly obsolete linear furrows ; 

 anterior lobe larger tban all tbe remaining portions of tbe glabella between 

 It and tbe neck furrow. 



JSeck segment a little bigber in tbe middle, (wbere it is provided witb a 

 minute tubercle), tban tbe glabella. Strongly arcbed upward (not for- 

 ward,, and more tban twice as wide antero-posteriorly as one of tbe tbora 

 cic segments ; neck-furrow deep, broad and arcbed wiib tbe neck-segment. 

 Eyes comparatively large, or balf as long, and (bebind). nearly as prominent 

 as an}^ part of tbe glabella, located witb tbeir posterior margins opposite tbe 

 neck-furrow, aud less tban balttbeu- own lengtb in advance of tbe posterior 

 margins of tbe cbeeks ; visual surface ventricose, or sub-bemispberical, 

 smootb, or even polisbed. as seen under a good pocket lens, but wben ex- 

 amined by a bigb magnifying power, sbowing numerous, regularly dis- 



