FOSSILS OF THE OOLITE. 



which is found in the upper marls, or limestones sometimes met 

 vith in their place : different species of Terebra'tula (Jigs. 88, 89), 



Fig.88. Terebrat.globa'ta. Fig.QQ. Tereb. spino'sa. Fig. 90. Ammonites Brongnia'rtil 



which seem to belong more particularly to the lower o'olite, as well 

 as a small globose species of ammonites (fig. 90). 



49. In the limestones proper, different species of ammonites 

 (Jig. 91) are found; various species of pleurotoma'ria (Jig. 92) 



Fig. 91. Ammonites stria'lulus. Fig. 92. Pleurotoma'ria cono'idea. 



which seem to be characteristic, and a great number of shells of 

 divers kinds, are met with. Encrini'tes, frequently very nume- 

 rous, which are chiefly referred to the pyriform species, apiocri'- 

 niles, are sometimes found on the very spot where they lived, 

 attached to the solid materials forming the bottom of the sea of that 

 epoch, and covered by successive deposits of the earthy matter of 

 which it w^as constituted. \ 



50. An important fact is connected with the marls and fissile 

 limestones which form the first of the o'olite system: the first, or 

 most ancient fossil mammals, were discovered in Stonefield slates. 



48. What fossils are characteristic of the o'olite ? 



49. What fossils are found in the limestone proper of the o'olite series? 



50. What important fact is connected with the fissile limestone and marl* 

 wf the lower o'olite ' 



