PLATE XIV. 



PAGE. 



Figs. 1-3. PrcETUS precursor Herrick 509 



1. Head and portion of thoracic segments. Cuyahoga shale, Moot's run, Licking Co. 



2. Glabella of the same species. 



3. Facets of the eye prominence, magnified. 

 Figs. 4-5. Ph^thonides spinosus Herrick. 



4. Glabella and portion of the head, twice natural size. Cuyahoga shale, Lickiugland 



Ashland counties. 



5. Pygidium of the above. 



Fig. 6. PHILLIPSIA MERAMECENSIS Shumard. 



Pygidium. enlarged two diameters. 

 Fig. 7. PrcETuS minutuS Herrick. 



7. Greatly enlarged. It is probable that this is a young specimen of Prcetns precur- 



sor. Intermediate forms show that the length of the axial portion of the glabel- 

 la varies with age. This specimen is almost microscopic. Moot's run. 



Fig. 8. Phillipsia serraTicaudaTa Herrick. 



8. Pygidium and its markings. 



Sd. Portion of head. Upper (Keokuk) layers of Waverly at Newark. 

 Fig. 9. Ph^sSTHOnides immaTurus Herrick. 



Pygidium. Probably immature or depauperate forms of P spinosus. This form 



occurs in the shales, while the typical specimens are from the lime concretions 



of the same strata, Cuyahoga shale, Cuyahoga Falls, 40 feet below the coal 



measure conglomerate. This form is generally labeled P. lodiensis by collectors. 



Figs. 10-11. PmJThonides OCCIDENTALS Herrick. 



a. Poption of head, enlarged two diameters. 



b. Pygidium, natural size. Kinderhook division (conglomerate I) Granville. 

 11. Hypostome of some trilobite, perhaps Phillipsia seraticaudata Herrick. 



Fig. 12. PRCETUS sp? (perhaps haldemani). 



Shales near base of Waverly, cnie mile east of Harlem, Licking cou nty 

 Fig. 13. PRCETUS (?). , ' 



Portion of head from the upper division. 

 Figs. 14-15. PrcETUS AURICULATUS Hall. 



14. Reduced one-hal f. Xinderhook freestone, near Granville. 



15. Pygidium of unknown trilobite (perhaps Phaethonides) from upper division ( Bur- 



lington) near Newark. 



Fig. 16a. PrcETUS precursor Herrick. 



A raiher immature specimen. Cuyahoga shale Lodi, Ohio. 



Fig. X&b-c. Ph^Thonides spinosus Herrick (?) . 



Pygidium apparently of this species (rom -shales of Cuyahoga strata at Lodi. In 

 the fourth volume of the Bulletin of Denison University these pygidia and the 

 associated heads were recognized as a distinct species (Phillipsia? cousors) but 

 the attempt to unite the characters of two genera should not have been made. 

 We have since found the forms connecting such glabella; with typical Prostus 

 pramaturus, which species is typically represented in the concretions at the 

 same place. The pygidia can hardly be other than depauperate forms of P. spi- 

 nosus of the same horizon. 



