41 



Arth. 



bia, and is full of worm burrows (ScoUthus.) The Scotch 

 geologists, who have so well worked out the extraordinary 

 structure of their Western Highlands, where our Appalachian 

 formations and fossils are represented in their normal order, 

 regard the so called sea weeds of ]^o, /and ]Vo. //as worm bur- 

 rows, tracks and excrements, and report them crowding and 

 traversing in all directions most of the sand beds which were 

 deposited before the deep sea limestone age. See Journal 

 Geol. Soc. Lond. 1888. See also Dawson's Rusiclinites. 



Artisii. See Cordaites serpens. XIII, 



Arvicola didelta, Cope. Proc. A. P S. 1871, p. 89, fig. 15 

 enlarged, <^, 5, c, d. Teeth of an extinct mouse found in the 

 bone cave at Port Kennedy, Chester Co. Pa. See Appendix 

 for 'figures, 



Arvicola hiatides, Cope. The same, p. 91, fig. 18 enlarged? 

 a, 5, c, 



Arvicola involuta, Cope. The same, p. 89, fig. 16. 



Arvicola sigmodus, Cope. The same, p. 90, fig. 17, ^, 5, g. d, 



Arvicola speothen, Cope. The same, p. 87, fig. 13. 



Arvicola tetradelta, Cope. The same, p. 88, fig 14. 



Asaphus canalis. See Isotelus canalis. // c, III h, 



Asaphus Goryphmus. See Proetus coryphaeus. Vb, 



Asaphus {Isotelus) iowensis. Owen. Geo. Wis., Iowa 



OvY. A I 



