370 HENRY B. KUMMEL 
mixed with varying amounts of quartz sand and fine earth, the latter 
of which contains much carbonate of lime in a powdery state. Where 
purest the marl has a dark-green or bluish-black color. The upper 
part of the bed contains progressively less greensand and is more 
clayey. The fauna is large (121 species, Weller), and is allied with 
that of the Marshalltown and Merchantville beds, while the character- 
istic forms of the Magothy, Woodbury, and Wenonah are absent. 
The formation has a maximum thickness of about 40 feet, diminish- 
ing southward to 25 feet or less. It corresponds in general to Cook’s 
Lower Marl, although locally beds referred by him to the Lower Marl 
have proved to be the Marshalltown. It rests conformably upon 
the beds below and grades upward into the Red Bank sand, or where 
that is absent into the Hornerstown marl. 
Red Bank sand.—The Red Bank sand is for the most part a fairly 
coarse ferruginous yellow and reddish-brown quartz sand, locally 
indurated by the infiltration of iron. The lower beds are in many 
places somewhat clayey. The Red Bank fauna has come chiefly 
from these clayey layers. In its essential features it is a recurrence 
of the Lucina cretacea fauna of the Magothy, Woodbury, and Wenonah 
formations, and differs in important respects from the Navesink fauna 
immediately below. It occurs only in the northern part of the coastal 
plain where its maximum thickness is too feet, but it thins out and 
disappears midway across the state. It is the Red Sand of Cook and 
earlier writers but does not include certain sands in the southern 
portion which were correlated by him with the Red Sand of Mon- 
mouth County. With the overlying Tinton bed, it is the uppermost 
of the beds correlated with the Monmouth formation of Maryland. 
Tinton bed.—A lense of green indurated clayey and sandy marl, 
having a thickness of from ro to 20 feet, overlies the Red Bank sand 
in Monmouth County. Its fauna is more closely allied to that of 
the Navesink than of the Red Bank and is characterized by large 
numbers of crustacean claws of the genus Callianassa. It is Cook’s 
“indurated green earth,’’ regarded by him and other writers as a 
part of the Red Sand, but in view of its faunal and lithologic differences 
it deserves some separate recognition. 
Correlation oj the Magothy-Tinton beds——The assemblage of 
fossils making up the faunas of the beds from the Magothy to the 
