SUBCLASS I 



TRILOBITA 



21 



Fig. 1389. 

 Froetus hohemicus Corda. 



Pic. 1390. 



Philli'pina gemimdifera 

 Phill. Lower Carboni- 



Family 15. Proetidae Corda. 



Small Opisthoparia ivith cephalon and pygidium nearly equal, free cheeJcs large, eyes 

 long, and dose to the glahella. Thorax with eight to ten segments. Ordovician to 

 Permian. 



Proetus Steiiiinger (Figs. 1351, 1364, G; 1389). Glabella witliout deep lateral 

 furrows. Pygidium smaller tlian cephalon. 

 Ordovician to Carboniferous ; Europe, 

 Asia and America. 



Gyphaspü Burmeister. Similar to 

 Proetus, biit with a strongly elevated 

 ridge which surrounds the glabella out- 

 side the dorsal furrows. Glabella with 

 prominent basal lobes. Ordovician to 

 Devonian ; Europe and America. 



Haploconus Raymond. Similar to 

 Gyphaspis, but without the basal lobes on 

 the glabella. Type, Bathyurus smithi 

 Billings. Ordovician ; North America. 



PhilUpsia Portlock (Fig. 1390). 

 Similar to Proetus, but with large pygi- 

 dium, and tosal lobes on glabella. This KÄt?r*ÄXr' fS" ' ■""""■ '"^ 

 genus survived all other trilobites, but 



became extinct with the close of the Permian. Carboniferous and Permian ; 

 Europe and America. 



Family 16. Aeglinidae Pictet. 



Opüthoparia with large glahella and eyes which occupy nearly the whole area of the 

 free cheeks. 



This genus has the glabella strongly convex, 

 prominent, smooth ; fixed cheeks suppressed ; 

 eyes very large ; thoracic segments five or six ; 

 pleura grooved ; pygidium large, with short axis, 

 Ordovician ; Europe. 



Family 17. Lichadidae Corda. 



Opisthoparia with large cephalon and pygi- 

 dium, the glahella greatly modified hy the peculiar 

 development of the lateral furrows. Thorax with 

 nine or ten segments. Pygidium with short 

 axial lohe, and the pleural lobes modified in 

 various ivays. Oixlovician to Devonian. 



Lichas Dalman (Figs. 1364, 7; 1392). 

 The glabella is broad, with axial furrows which 

 do not reach the neck furrow. Occipital lobes are present. Pygidium flat, with 

 the pleural lobes divided by furrows into two pairs of lobes with short free ends, and 

 a median flattened lobe. Ordovician and Silurian ; Europe and America. 



Amphilichas Raymond {Platymetopus Schmidt). Glabella large, divided longi- 

 tudinally into three lobes by a pair of axial furrows which jom the neck ring. 

 Ordovician ; Europe and America. r ., i , 



Gorydocephalus Corda {¥i^. 1338,^ ; 1393). GlabeUa with three pairs of side lobes, 



VOL. I ^ ^ 



Äeglina Barrande (Fig. 1391). 



A n 



Fio, 1391. 

 Aefilitia prisca Barr. Ordovician (Etage D) ; 



Vosek, Bohemia 

 (after Barrande), 



A, Nat. size. 7.', ü, enlarged 



