96 BULLETIN: MUSEUM OF COMPARATIVE ZOÖLOGY. 
stretch of coast between Mosquito Cove aud the east point of Luces 
Harbor. Here the highway is located upon a narrow strip of low coast 
plain, following an inland bluff whose base, to a height of 30 feet, is 
composed of the black shales of the Richmond beds, which stand almost 
vertically. Above these is a firm scarp rock of old Soboruco 30 feet 
Fiaurn 32. Bluff, West Bank of Mouth of Great River, near Round Hill 
Point, Montego Bay. 
a. Back coast country of old White Limestone. 
b. Yellow Marls allied to Manchiomeal Formation. 
c. Soboruco near sea level. 
thick. This Soboruco is made up of gigantic coral heads of many spe 
cies, as shown on Plate XXIX, The heads are embedded in a matrix of 
dirty white and yellow marl, and have been so altered by induration 
and erystallization that they could be broken by the hammer only with 
great difficulty. The summit of this reef constitutes a level which 1$ 
visible for several miles. It corresponds in altitude, thickness, and 
lithologie character with that elsewhere noted at the mouth of Priest 
Faure 83. Old Reef unconformable on Old Eocene Clays near Barbican. 
a, Subvertical Richmond Formation. 
b. Reef Rock. 
man River near Northeast Point in Portland. This Soboruco is th? 
oldest not only by occurrence, but also in appearance ; the coral heads 
are more consolidated and crystallized, and the embedding material i$ 
of a yellow color indicative of long oxidation. "The unconformable com 
tact of this old reef with the almost vertical Richmond beds is clearly 
shown in a bluff over 100 yards in length. 
