194 TRANSACTIONS OF THE [May 18, 
well marked in Wales, where the species P. Davidis was discov- 
ered, and it is fully represented in Sweden. 
The other two sub-zones of the Paradoxides beds are not known 
to be represented in America, and so far as the author knows, 
have not been recognized outside of Scandinavia. That of P. For- 
chammeri is contained in the Andrarum limestone, a very rich 
repository of Cambrian forms, where the Paradoxides fauna 
may be said to have culminated. The higher of these two sub- 
zones contains only the dying remnants of this fauna and is 
known as the Zone of Agnostus levigatus. Rare remains of a 
Paradoxides related to P. Tessini have been found in it. I. D. 
Wallerius has lately described a number of new genera, eo 
and varieties from this sub-zone in Sweden. 
The following is in brief the range of the American subfau- 
nas of Paradoxides so far as known: 
Sub-zone of P. lamellatus—New Brunswick only. 
Sub-zone of P. Eteminicus—New Brunswick, Newfoundland 
and Massachusetts. 
Sub-zone of P. Abenacus—New Brunswick and Newfound- 
land (doubtfully in the latter province). 
Sub-zone of P. Davidis—Newfoundland only. 
DESCRIPTIONS OF GENERA AND SPECIES. 
PHYLLOPODA ? 
As compared with the Phyllopod crustacean of the Olenus 
and higher zones the fossils described below are very small. 
Their minuteness is an obstacle to the study of their characters, 
for there has been suflicient molecular movement in the shales in 
which they are imbedded to obscure the surface markings of 
such delicate fossils as these. They are supposed to be crusta- 
cean on account of the long, straight hinge line and weak um- 
bones and their defined bordering rim. 
LEPIDITTA.* 
Obliquely semi-circular or semi-elliptical bivalves, wide on the 
anterior half of the valve and having a long, straight hinge line; 
umbones in front of the mid-length of the hinge, low or but 
moderately elevated. 
LEPIDITTA ALATA (Plate XV., figs. la and 1b). 
Lepiditta alata, Trans. Roy. Soc. Can., Vol. III., pt. iv., p. 61, 
pl. vi., figs. 16, 16a. 
* Trans. Roy. Soc. Can., Vol. III.. pt, iv., p. 61. 
