22 P- T. CLEVE. 



account I would believe that the formation belongs to the youngest division of the rniocene 

 age, or to the pliocene time. 



Anguilla is a long and narrow island stretching from northeast to southwest about 

 26 kilometers. It is a flat limestone plateau of about 70 meters, in hight at the northern 

 end and slowly dipping down to the sea in the southern part. At the abrupt sea-cliffs 

 on the northern coast it is easiest to get information about the geology of the island. In 

 one cliff north of Sandy Bay the bottom-rock is visible. It is a dark amygaloidal trap- 

 pous rock, containing nodules of Thomsonite and Laumontite. This trappous rock is co- 

 vered by a yellowish soft limestone-bed containing many fossil corals and echinoderms etc. 

 South of Sandy Bay there are, near the sea, cliffs composed of almost horizontal strata. 

 Furthest down near the sea are beds of a grayish or yellowish marl with many casts of 

 shells, fragments of crabs etc; they are covered by beds of coral-fragments and shells of 

 Pecten. Above that bed occur strata of marls covered by coralline limestone and a härd 

 white limestone-rock with very few fossils. The latter stratum is the surface-rock of the 

 island and it contains many fissures filled with a breccia of angular limestone pieces and 

 a red härd rock. In that breccia, which contains phosphate of lime, are found landshells 

 of species still living in the island and bones and teeth of an extinct rodent Amblyrhiza 

 inundata Cope. of a very large size. 



The fossils of the marls and limestones of Anguilla are generally badly preserved, 

 most of thern being only casts, which makes their deterraination very difficult. Among 

 the fossils are Natica phasianelloides d'Orb, widely distributed in the rniocene beds of the 

 West-Indies, Natica Canrena L., and species of Strombus, Cassis, Conus, Cyprcea, Turritella, 

 Scalaria, Solarium, Oliva, Ficula, Pecten, Venus, Ludna, Lima, Cardium, Cardita etc. Very 

 numerous are the echinoderms, and mostly well preserved. They have already been descri- 

 bed by Guppy. Of corals a great number is found, and also several foraminifera. Among 

 the fossils are large calcarious tubes of Teredo, also found in Puerto Rico. The formation 

 of Anguilla may be classed as rniocene, as is made probable by the paleontological resear- 

 ches of Guppy*). 



S:t Martin is an island of almost triangulär outline, formed by conical hills, some 

 of which are about 400 meters high. From north to south the island is about 14 kilo- 

 meters long. Around the shores are many large lagoons and in the interiör several rivu- 

 lets and permanent springs- Having visited only the southern part of the island I can 

 only give an account of that part. In the southeastern corner rise abrupt seacliffs of re- 

 gularly stratified rocks, mostly of a kind of silicious limestone of a darker or lighter 

 grayish or greenish colour, and often very härd. The strata are almost horizontal and do 

 not contain fossils. In many places I have seen black, brown or greenish garnet in these 

 rocks. The strata are sornetimes intersected by dikes of greenstone or in some spöts by 

 veins with silicates of copper. Between the Dutch town of Philipsburg and the south- 

 eastern point the strata are penetrated by a dike of light coloured diorite resembling sye- 

 nite, sending branching veins into the surrounding rock, intruded between the strata and 

 deranging them, so that they dip southward 40° and strike E — W. On the southeastern 



o 



*) Quart Journ. Geol. Soc. Lond. Vol. XXII pag. 297. 



