102 PALEOZOIC PALEONTOLOGY. 
above them the sandstone facies of the formation. From the cal- 
careous beds at this locality the following species have been identified : 
. Favosites sp. undet. 
. Bryozoa several undet. sp. 
. Pholidops ovata Hall. 
. Stropheodonta magnifica Hall. 
. Eatonia peculiaris (Con.). 
Spirifer murchisone Castel. 
. Metaplasia plicata n. sp. , 
. Anoplotheca flabellites (Con.). 
. Platyostoma ventricosa Con. 
10. Tentaculites elongatus Hall. 
. Dalmanites sp. undet. 
DO 2 oS Or H © WH 
as) 
js 
pom 
ESOPUS GRIT. 
This is one of the most persistent formations in the Delaware valley 
region of New Jersey, and forms the: crest of the Wallpack ridge 
throughout the greater part of its extent in the State. It is a nearly 
black, gritty, resistant rock, in which cleavage is frequently developed 
to a high degree. Usually it is difficult to distinguish the bedding 
planes, because of the slaty cleavage, but when they can be recog- 
nized, the fucoid “candagalli” markings are often more or less clearly 
to be seen. Aside from these indefinite, supposed fucoid or sea-weed 
markings, fossils are exceedingly rare in the whole formation. A 
single, imperfect specimen of an inarticulate brachiopod, probably 
Lingula or Orbiculoidea, has been found in an outcrop of this forma- 
tion near Flatbrookville, but no other specimens have been observed. 
In his report on Pike and Montgomery counties, Pennsylvania, 
White* mentions the presence of fossil brachiopods in this forma- 
tion, but a careful search in New Jersey has failed to bring to light 
any other than the single specimen already mentioned. It is possible 
that the fossils mentioned by White were secured from the shaley 
beds at the base of the superjacent Onondaga limestone, as these beds 
frequently resemble, in a measure, some of the beds of the Hsopus 
grit, and they are often more or less fossiliferous. The average thick- 
ness of the formation has been estimated as about 375 feet. 
* Second Geol. Surv. Penn., Rep. G. 6, p. 122. 
