October, 1913. New Trilobites — Slocom 77 



curve, but the type specimen, now in the paleontological collection of 

 the University of Chicago, agrees with the specimen here described. 



Localities and horizons. — The type specimens were from the Rich- 

 mond beds in Butler County, Ohio, and Richmond, Indiana. The 

 specimens here described are from the Lower Maquoketa beds, Cler- 

 mont, Iowa. 



Genus SPILEROCORYPHE Angelin 1852. 



Cephalon convex, genal angles spined; glabella spheroidal anteriorly, 

 lateral lobes obscure; eyes prominent; facial sutures cut the lateral and 

 frontal margins. Thorax composed of 8-10 segments; axis narrower 

 than the pleurae; pleural segments terminate in short reflexed spines. 

 Pygidium composed of three segments, the extremities of the anterior 

 one produced into long spines. Type S. granulata. Range Ordovician, 

 Europe and North America. 



Sph.*rocoryphe maquoketensis sp. nov. Plate XV, Figs. 1-4. 



Type specimens Nos. P 11152A, 11152B, 16954 and 17051 Field 

 Museum. 



Cephalon sublunate in outline, convex, distinctly trilobed; anterior 

 margin truncated; posterior margin nearly transverse. Glabella very 

 prominent, anterior lobe globular, produced beyond the anterior mar- 

 gin; comprising fully three-fourths the bulk of the glabella; a single 

 pair of shallow, transverse, lateral furrows meet just behind the lateral 

 lobe of the glabella and separate it from a pair of indistinct lateral 

 lobes; occipital segment arched slightly forward, its posterior margin 

 abruptly elevated, surface sloping into the furrow; occipital furrow 

 shallow, not well-defined except at its extremities. Dorsal furrows 

 well denned, much wider and deeper at the junctures with the occi- 

 pital and glabella furrows, diverging somewhat in passing forward from 

 the posterior margin of the cephalon until near the anterior margin 

 where they abruptly converge until they meet forming the anterior 

 marginal furrow; cheeks depressed convex, greatest elevation at the 

 palpebral lobes which are situated about midway between the posterior 

 and anterior margins and one-third the distance from the dorsal fur- 

 rows to the genal angles; antero-lateral margins of the cheeks forming 

 an elongate sigmoid curve; free cheeks triangular, small, less than one- 

 half the size of the fixed cheeks; eyes large, prominent, globular; the 

 facial sutures originate on the lateral margins well in front of the genal 

 angles, pass inward and slightly backward over the palpebral lobes, 

 thence forward to the anterior margin; the genal angles merge into 

 stout, recurved spines; the posterior marginal furrows are continuations 



