PACKARD.] ° THE ORDER PHYLLOCARIDA. 451 
E. armatus (Hall) = £. punctatus (Hall), Hamilton group, Devonian, New York. 
E. pustulosus Whittield, 1. c. 38, Erie shales, Devonian. Ohio. 
E. multinodosus Whittield, 1. c. 33, Erie shales, Devonian. Ohio. 
Genus DISCINOCARIS Woodward, 1866. 
Like the upper valve of a Discina, but with a se acaumenaie si ees 
which cuts the disk nearly to its center. 
D. browniana Woodward, Proc. Geol. Soc. 502, 1866. 
Genus SPATHIOCARIS Clarke, 1882. 
Differs from Discinocaris in the presence of 
the “rostrum” or plate acting as another valve 
to cover the cleft, and also in its more nearly 
circular outline (Clarke). 
S. emersonii Clarke, Amer. Jour. Sc. xxili, 477, June, 1882. 
Fig. 71 A.—Echinocaris muiti- 
Genus LISGOCARIS Clarke. nodosus. After Whitfield. 
Carapace in one piece, without evidence of 
dorsal suture. Periphery subpentagonal, lateral 
edges parallel, making sharp angles with the 
two anterior edges, which are re-entrantly curved, 
and meet in the axis of the carapace. As in _. AL Pee : 
Spathiocaris, there is a cleft beginning centrally ate Weim sulents. 
at the highest point of the carapace. 
L. lutheri Clarke, 1. c. 478, 1882. 
APTYCHOPSIS Barrande, 1872. 
Differs from Peltocaris in the rostrum being triangular instead of 
parabolical; and from Discinocaris in having no suture indicating the 
separation of the two principal valves. 
A. primus Barr. 1. ¢. 457, Pl. 33, 1872. Bohe- 
mia. 
Genus DicTyocaris Salter (1860). 
Carapace ample, bent along the dor- 
sal line, but not two-valved, largely 
reticulate, the area of the reticulations 
being convex. The shape of the car- 
apace is rudely triangular, pointed or 
rounded in front, truncate and pro- 
Fig. 72.—Discinocaris browniana, natural size, duced behind, and margined along the 
side view and disk, with the wedge-shaped ros- hinder and moana edges by a strong 
trum in situ. After Woodward. furrow. 
D. slimoni Salter, Ann. Mag. Nat. Hist. vol. 5, 1860, 162. 
D. ramsayi Salter, lc. 162. 
Genus DITHYROCARIS Scouler. 
Carapace large, apparently covering all but the last abdominal segment; 
“the rostrum minute or possibly (but not probably) absent” (Salter). 
