216 IOWA STUDIES IN NATURAL HISTORY 
strait. Some evidence of the former presence of the sea is to 
be found in the loose marly deposits occuring in several places 
between English Harbor and St. Johns. Such a deposit a few 
hundred yards north of the Dockyard yielded quantities of 
slightly bleached shells,—some of the valves still in apposition. 
They belong to recent forms most of which were found living in 
the neighboring bays.. The following genera are the commonest : 
Arca, Cardium, Isocardia, Levicardwm, Cythere, Donax, and 
Pecten among the pelecypods; and Polynices, Cerithium, 
Astraluum, and Strombus among the gastropods. Some 
branches of the coral Oculina are also common. Similar deposits 
occur near the Botanical Gardens at St. Johns. 
The northeastern belt is the limestone area of Antigua. The 
overlying soil is fertile, tractable, and marly; the region is roll- 
ing, and there are a few hills and ridges ranging from 100 to 400 
feet above the sea. The strata dip gently to the northeast, are 
slightly folded in places, and are cut by a number of strike 
faults, some of which have considerable throw. The unweath- 
ered limestone is fairly pure, crystalline, and hard. It is Oli- 
gocene in age as the fossils attest, hence it is much older than 
the white limestones of Barbados and more nearly contempor- 
aneous with the radiolarian earths and globigerina marls of the 
Scotland district. Good exposures may be seen at Hodge Point 
and vicinity in the extreme northern part of the island and at 
Lynch’s on the northeast shore of Willoughby Bay, also both 
north and south of Nonesuch Bay on. the windward coast. The 
limestone is abundantly fossiliferous and a representative col- 
lection of well preserved fossils was obtained. In places the 
limestone is crowded with smooth, round, disc-shaped forms 
which have been called ‘‘Orbitoides mantelli.’’ This doubtful 
_foraminifer is fully three inches in diameter and from one-six- 
teenth to one-eighth of an inch thick. At a locality on the wind- 
ward coast an impure limestone stratum was found in which 
similar forms only one-fourth of an inch in diameter and from 
one-fifteenth to one twenty-fifth of an inch thick oceur densely 
erowded in the matrix. In places they weather out and hun- 
dreds of perfect specimens were obtained. Several genera of 
pelecypods also were found, the most common being Pecten 
which is represented by two or three species and Ostrea, 
