%8 PALEOZOIC PALEONTOLOGY. 
The fauna of the Rondout formation, made up almost exclusively 
of members of the genus Leperditia, is a peculiar one, and must indi- 
eate some peculiar conditions of environment, but what these condi- 
tions may have been we do not know. 
MANLIUS LIMESTONE. 
The Manlius, or “Tentaculite,” limestone of the older New York 
reports is a somewhat thinly-bedded, knotty, dark blue or almost 
‘black limestone. It is the bed which constitutes the quarry stone, 
and its outcrop may be traced throughout the entire length of the 
Wallpack ridge in New Jersey by the line of active or abandoned 
quarries and lime-kilns, its upper portion being the only limestone 
which is extensively used in this portion of the State for the manu- 
facture of lime. The total thickness of beds in the Nearpass section 
referable to the formation is thirty-four feet and eight inches. 
The fauna of the Manlius limestone is not a large one. Ostracodes 
still persist, but associated with them in some beds are several species 
and many individuals of brachiopods, with some gastropods and 
pelecypods and an occasional cephalopod. Specimens of Tentaculites, 
which are so abundant in this formation at some localities in New 
York State, and which gave rise to the older name of the formation, 
are among the rarest members of the fauna in New Jersey. One 
of the most characteristic species of the fauna, although it has not 
been noticed in the lowest beds, is Spirifer vanuxemi, and the life 
zone represented by the Manlius limestone may be called the Spirifer 
vanuxemt zone. 
Locality 2 A.—In the Nearpass quarry, where this formation has 
been studied in most detail, several beds have been recognized, as 
shown in the following section, and from each bed the species enume- 
rated were collected : 
2 A*'. Hard, bluish-black limestone. © tb: 
1. Stromatoporoid masses. 
2. Megambonia aviculoidea Hall. 
3. Leperditia alta (Con.). 
4. Beyrichia sp. andet. 
2 A**. Hard, bluish-black stromatoporoid limestone. 4 ft. 6 in. 
Stromatoporoid masses. 
Leperditia alta (Con.). 
. Beyrichia manliensis n. sp. 
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