TlIK BUIT.DIXC OF AX ISLAND. II 



siiinl left in the bottom of the glass. Pouring a little clear water over it so as 

 to cover it, we then examine this sand with our lens, and we gel some interest- 

 ino- results. Among a multitude of sand grains, of various si/es, we shall find 

 some, or perhaps manv, of the round shells which we first saw in the solid rock, 

 and we shall also from time to time meet with other forms, some of them very 

 heautiful, others onlv odd ; look, for example, at the beautiful coiled forms 

 sketched on Plate H. and near them the curious jointed form resembling a 

 sugar-cane. 



These tiny shells are the remains of minute creatures caWg^X Foraminifcra, 

 and are found in most sea-sands. Hence, our examination of the marl rocks 

 lias alreadv shown us that thev'were built up in the sea. B\' wav of making 

 the matter certain bevond all dispute, however, we may compare the forms 

 which we get out of the rocks in the manner al)Ove described with the forms 

 which we get from the bottom- of the present sea. This comparison is made 

 in the accompanying Plate, where the forms, roughly sketched in the upper 

 half, are those of foraminiferous shells from our marl and limestone rocks, 

 while the forms sketched in the lower part of the Plate are those of similar 

 shells found in sand taken from the bottom of Christiansted Harbour or 

 other shallow waters around our shores. 



These minute shells in the rocks are found not at Anna's Hope only but 

 at manv other places on the ishuid where the marl and limtsione formation 

 shows itself. The globular shells in particular are very abundant, and some of 

 the others also in special localities, while others again are rare and have to be 

 searched for. At all events, these interesting little shells are sufficiently 

 spread through our marl formation to prove that it has in all parts the same 

 origin, namelv, that it has ever\\vhere been built up, layer by laver, in the sea. 



About the Foramixifera. 



Having rendered us so important a service, these shells may, tor a brief 

 spact-, claim attention to their own history. Thev were once the tenements 

 of living creatures, as their representatives in the ])resent age now are in the 

 oceans and seas known to us; and the study of the existing members of the 

 family enables us to understand those which are extinct. Some species, 

 indeetl (the globular shells, for example), are both ancient and recent, being 

 found as shell remains in the rocks and likewise as living creatures in the 

 ocean. 



Zoologists class all these minute animals as belonging to the Protozoa 

 (tirst animals), so named on account of the apparent simplicity of their 

 structure. Mainlv thev appear outwardlv to be tinv i)ieces of living jellv, by 

 which the shellv substance is deposited. By this tleposition a small cell or 

 chamber is formed. Some kinds never, or seldom, advance be\ond this one- 

 celled condition, but nearlv all kinds go on adding new cells to the first. 

 Some add the cells in a straight, or mavbe slighth' curved, line; but the 

 majoritv of the species add the cells in a distinctlv curved form, either a tlat 



