37 



Arch. 



Pa. 



Archymilacris parallelum (i. e. the beginning of Cock- 

 roaches). Sc udder. 

 Boston Soc. Nat. Hist. 

 Vol. 8, 1879, p. 85, plate 

 6, fig. 6, in the Mauch 

 Chunk formation, 

 under Campbell's 

 ledge, in the gap, at 

 Pittston, Luzerne Co. , 

 XL 



p(-6-f.6 



See White's report, G7, p. 41. 



Arionelhcs quadrangularis . See Agraulos quadrangu- 

 laris. Lower Cambrian. 



Aristozoa. Specimen in Carll & Kandall's collections in 

 Warren Co., Pa. C. E. Hall, Eeport of 1875, in Proc. Amer. 

 Phil. Soc, Phila., January 5, 1876.— F///^, /X. 



Arthrolycosa antiqua. Harger. A fossil spider of the 



Coal Age, found in a 

 Mazon creek nodule of 

 the Hlinois coal field. 

 Zittel's Handbuch der 

 Palaeontologie, 1885, 

 Vol. 2, page 735, fig. 

 2{)d^natu,ral^\7.Q.-XLLL. 

 A more perfectly pre- 

 served spider, from the 

 Colebrookdale coal 



measures of England, is added for comparison. Zittel (after 



Woodward), fig. 913. 



Arthrophycus harlani. ( Fucoides harlani. ) Hall, page 

 46, fig. 5, 1 and 2. Vanuxem, page 71, fig. 10. Rogers, page 

 821, fig. 623. See Conrad, An. Rt. N. Y., 1838. IV. Medina 

 Sandstone formation. LVb. 



Note. See Harlania halli. There is a disposition among 

 geologists to regard these forms as not plants, but worm-bur- 

 rows. C. E. Hall collected them for the Survey in Schuylkill 

 and in Mifflin counties. In the mountain gaps of Blair Co. the 

 uppermost thin beds of the White Medina (LVc) mottled red 

 and gray are often covered with a net work of obscure impres- 

 sions of these seaweeds, beneath greenish non fossiliferous 



