406 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 



DESCRIPTION OF PLATE z^ 



PAGE 



Olenelhis gilberti Meek ( See pi. 43) 324 



Figs, i, 2; and 3. Cephalons crushed and flattened in a dark argillaceous 

 shale from locality (31a), near Pioche, Lincoln County, 

 Nevada. U. S. National Museum, Catalogue Nos. 15411a, 

 15411&, and 15411C, respectively. 



These are the specimens to which Meek assigned the name 

 Olenellus gilberti. They were figured by White, 1877, pi. 2, 

 figs. 2,b, 3c, and 3a, respectively. 



4 and 4fl. Top and side views of a cephalon preserving its con- 

 vexity in a granular limestone from the same locality as that 

 given for figs. 1-3. Natural size. U. S. National Museum, 

 Catalogue No. 1541 irf. 



This is the specimen upon which Meek based the species 

 Olenelhis hoivelli. It was figured by White. 1S77, pi. 2, 

 figs. 4a-b. 



5. Small hypostoma X 3, associated with specimens of the cephalon 

 of this species at locality (i/'), south of Silver Peak, Esmeralda 

 County, Nevada. U. S. National Museum, Catalogue No. 

 56825a. 



6 and 7. Cephalons compressed and distorted in fine arenaceous 

 shale. X 2. Drawn from specimens found in locality (13;), 

 Clayton Valley^ Esmeralda County, Nevada. U. S. National 

 Museum, Catalogue Nos. 56826a and 56826&, respectively. 



8. Cast of the inside of the cheek and genal spine and a small 



intergenal spine. Natural size. Locality {ip), south of Silver 

 Peak, Esmeralda County, Nevada. U. S. National Museum, 

 Catalogue No. 56825^7. 



9. A compressed and slightly distorted dorsal shield. Natural 



size. Locality (30), 8 miles west of Pioche, Nevada. U. S. 



National Museum, Catalogue No. 15416a. 

 This figure was published by Walcott, 1886, pi. 21, figs, i, 



\a; and 1891, pi. 94, figs, i, la. In these publications the 



anterior lobe of the glabella was extended to the front border 



by error of the draftsman. 

 10. A small cephalon 2 mm. in length. X 6. Locality (i»0. south 



of Silver Peak, Esmeralda County, Nevada. U. S. National 



Museum, Catalogue No. 56827a. 

 Ti. A cephalon in which the antero-lateral angles are developed. 



X 10. U. S. National Museum, Catalogue No. 56828a. 



12. A slightly larger cephalon than that represented by fig. i, with 



large irftergenal spines, slightly developed genal angles, and 

 antero-lateral angles and spines. X 10. U. S. National 

 Museum, Catalogue No. 56828^. 



13. Fragment of a small cephalon X 4. showing intergenal ridge 



crossing the posterior margin. U. S. National Museum, Cata- 

 logue No. 568281-. 



