80 BULLETIN : MUSEUM OF COMPARATIVE ZOÖLOGY. 
Mollusea ocenr in these beds. The lumps in the marl are largely fossils ; 
three specimens are Echinoids! and one is a large Conus, two inches long. 
Casts of Natica and Cypræa were also recognized, as well as two species 
of coral, — one a simple form, the other a compound form, but both 80 
poorly preserved as to be indeterminate. None of these forms suggest 
the Bowden fauna except the simple coral, aud probably they represent 
a slightly earlier and preceding horizon. 
From Bog Walk Station to a point where the highway to Linstead 
crosses the railway track, one and a half miles due north, following the 
south margin of the basin valley, the surface exposures consist of later al- 
luvium. At the last mentioned point the railway cuts through an inlier 
of white limestone of the Cobre type. This exposure contains an abut 
dant molluscan fauna, but all the specimens are poor casts, among which 
Wy 
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Fieurn 25. Section of Northern End of Bog Walk Canyon, 
. White stratified Cobre Limestone with Marl Pit. 
. Conglomerate of small Igneous Pebble. 
. Buff colored Limestone, banded, 
. Buff, granular, laminated Marl, with little Conglomerate, oxidizing Red. 
. An Outlier to North of this Locality, which will be described later. 
CQ Hi O5 b rA 
the genera Bulla, Arca, Cardium, and Lucina are evident. No corals 0f | 
Echinoids were found. A few miles farther, at Linstead, the Moneagu? 
beds appear, apparently beneath this section. The aggregate thickness 
of the limestone of the Cobre section cannot be less than 1,000 feet, and 
is probably much more. 
The extent of the Cobre formation is not completely determined. wo 
have personally seen the formation only on the south side of the central 
portion of the island. Good exposures of it, are seen in Clarendon along 
the highway from May Pen Station, on the Montego Day Railway, and 
Chapelton. Here the limestone has the same general character as thal 
of the Bog Walk section, and constitutes the summits of the Minh? 
Mountains. Between the Minho River and Retreat,’ the limestone u 
underlain by more massive bedded layers resembling the Moneague for | 
1 Echinolampas or B. thiiopygus. : 
2 Not to be confused with Retreat in Trelawney, previously mentioned in dis 
cussing the Brownstown formation. 
