340 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 



of the city of York; (49c) just north of the railway station at 

 Emigsville, York County; (49b) 2 miles (3.2km.) northwest of 

 Emigsville in continuation of the ridge from which No. 49c was col- 

 lected ; (49e) I mile (1.6 km.) south of Mt. Zion Church and 4 

 miles (6.4km.) northeast of York; and (i2w) just west of Fruit- 

 ville, about 2 miles (3.2 km.) north of the city of Lancaster and 

 westward at various localities to the Susquehanna River, notably 



1 mile (1.6 km.) north of Rohrerstown on farm of Noah L. Getz, 

 Lancaster County; all in Pennsylvania. 



(47d) I mile (1.6 km.) east-southeast of Smithsburgh ; (476) 



2 miles (3.2km.) south of Keedysville, on Observatory Hill; and 

 (47f) at Eakles Mill, 2 miles (3.2km.) south of Keedysville; all 

 in Washington County, Maryland. 



(47) in a hard sandstone .75 mile (1.2 km.) up a little brook 

 opposite Gilmore on the south side of the Shenandoah River; (47g) 

 shaly sandstone on Mason Creek i mile (1.6 km.) east of Salem; 

 and (47c) on the south side of the Potomac River, 2 miles (3.2 km.) 

 west of Harpers Ferry bridge ; all in Virginia. 



(46) at the western base of the ridge of Knox sandstone [Saf- 

 ford] 5.5 miles (8.8km.) west of Cleveland; and (46a) upper por- 

 tion of Knox sandstone in the village of Rhea Springs, Roane 

 County ; both in Tennessee. 



(164a) argillaceo-arenaceous Montevallo shale 2 miles (3.2 km.) 

 north of Montevallo, Shelby County, Alabama. 



Fragments of a large Olenellns that may belong to this species 

 occur in (59m) Weisner quartzite in the Roan Iron Mine, Bartow 

 County, Georgia. 



OLENELLUS THOMPSONI CRASSIMARGINATUS, new variety 



Plate 35, Figs. 8-10 



Olcnellus thompsoni Walcott (in part) [not (Hall)], 1886, Bull. U. S. 

 Geol. Survey, No. 30, pp. 167-168, pi. 17, fig. i (not pi. 17, figs. 2, 4, and 

 g; pi. 22, fig. I ; nor pi. 23, fig. i = Olcnellus thompsoni) . (Copies the 

 original description given by Hall [1859, p. 59] and discusses species. 

 Figure i is copied in this paper, pi. 35, fig. 8.) 



Olcnellus thompsoni Walcott (in part) [not (Hall)], 1891, Tenth Ann. 

 Rept. U. S. Geol. Survey, pi. 83, fig. ib (not pi. 82, figs, i and la; not 

 pi. 83, figs. I and la = Olcnellus Ihompsoni) . (No text reference. 

 Figure ib is copied from Walcott, 1886, pi. 17, fig. i.) 



Tliis variety is founded on a number of specimens of the cephalon 

 with a broad, somewhat flattened marginal rim that in specimens of 

 the same size is proportionally broader than in Olcnellus thompsoni. 

 The palpebral lobe is also broad. 



