72 



FOSSILS. 



formation generally, the characteristic shells are the inoce'ramus 

 conce'ntricus (fig. 127), the plica'lula placu'nea (fig. 128), seve- 

 ral species of ammonites, and particularly the ammonites monile 

 (fig. 129), which is quite characteristic. 



Fig 126. JVu cula pectma'ta (shell and mould) 



Fig. 1-28. Plica' tula placu'nea. e'qualis. 



14. We find in the chalk marl the baculi'fes (fig. 130), and 

 turrUi'tes (fig. 131), different species of the first of which are 

 found in the highest part of the chalk formation. To these may 

 be added the scaphi'tes (fig. 132), some particular species of 



Fig. m.- Ammonites monile. Fig. UO.Baculi'tes. 



Fig. 131. Turrrili'tes 

 costa 'tus. 



ammonites (figs. 133, 134), the Ex'ogy'ra columba (fig. 135), 

 the O'sfrea carmata (fig. 136), the terebra'tula octo'plica'ta (fig. 

 137), which continue in the chalk. 



14. What animal remains are found in the chalk marl ? 



