726 



AETHROPODA 



PHYLUM VII 



Subfamily A. Ualmanitinae Reed. 



Phacopidae with more or less modified pentamcrous segmentation of the glabella, and 



usually ivith large cranidia and fijgidia. 



Dalmanitina Reed (Figs. 1353; 1356; 

 1398, i'^; 1407). Pentamerism of head well 

 marked, lobes of glabella distinct ; genal angles 

 rounded or with short spines. Pygidium 

 with few segments, rarely more than ten. 

 Ordovician and 

 Silurian ; Europe. 



Dalmanites Bar- 

 rande (Figs. 1337 ; 

 1398, G; 1408).' 

 Frontal lobe of gla- 

 bella detached. Pygi- 

 dium strongly mucro- 

 nate, with twelve to 

 Devonian ; Europe and 



. Fig. U07. 



Dalmanitina xodaUs (Bair.). Ordovician (Etage 

 D) ; Wesela, near Prague, Bohemia. Cephalon, i/] 



sixteen segments. Silurian and 

 America. 



Asteropyge Corda (Gryphaeus Green). Pygidium with five 

 pairs of marginal spines, and sometimes a terminal spine. 

 Devonian ; Europe and America. 



Proholium ffihlert. Cephalon with a snout-like anterior 

 prolongation. Devonian ; Europe and America. 



Subfamily B. Phacopinae Reed. 



Fig. 1408. 



Phacopidae loith qlahallar furrows nearly or quite obsolete, . , . , 



. -'. 7, 7 7 7 -'J- Dalmanites limulurus 



and pygidium small and rounded. (Green). Silurian ; Lockport, 



New York (after Hall). 



Phacopidella Reed {Acaste Goldfuss) (Figs. 1398, J; 1409). 

 Glabella with three pairs of ,^^5?^^^ faintly defined 



Ordovician and Silurian ; /!(F^-'''''^^™|k Europe. 



Phacops Emmrich (Figs. ^fe^/W 

 furrows, except occasionally ^^^'^'^..^^^M the last pair, obsolete. Silurian 

 and Devonian ; world - wide te=^?^^3^?=^ distribution. 



lateral furrows. 



Fio. 1409. 



Phacopidella downin giae 

 (Murch.). Silurian ; Lud- 

 low, England (after Salter). 



Fio. 1410., 



Phacops latifrons 

 Bronn. Devonian ; 



Gerolstein, Eifel 

 District, Germany. 



Fig. 1411. 



Phacops stcrnhergi Barr. 

 Devonian (Etage G) ; Hostin. 

 Bohemia (after Barrande). 



Trimerocephalus M'Coy. Eyes small and far forward. Devonian ; Europe. 



