764 ME. E. W. HAEMEE ON THE [Nov. 1 896, 



is considerably greater than that between the upper portion of the 

 Red and the Norwich Crags. 



I have been guided entirely by palseontological considerations in 

 attempting to separate, in these borings, the different horizons of 

 the Dutch Crag. The lines that I have drawn may or may not be 

 correct, and I am quite prepared to adjust them if necessary. But 

 even if they may have to be shifted higher or lower, it will not, I 

 think, affect the general conclusions, that three divisions rather than 

 two may be traced in these strata ; that Arctic shells are confined 

 to the highest zone ; and that there is an absence from the latter of 

 a number of extinct or southern forms which are found alike in 

 the Scaldisien and Walton deposits, but not in the upper horizons 

 of the English Crag. 



The difference between the three divisions of the Dutch Crag 

 comes out more distinctly when we confine our attention to the 

 more abundant or characteristic species. I subjoin lists of these, 

 extracted from the general list given by Dr. Lorie. 



List of the more abundant species of Mollusca from the 

 Pliocene Beds of Holland. 



A. From beds regarded by me as Diestien. 1 



Terebratula grandis, Blum. 



Anomia ephippium, Linn. 



Pecten opercularis, Linn. 

 „ vcntilabrum, Goldf. 



Limopsis pygmcea, Wood. 



Cardita orbicularis, Leathes 

 ,, chamceformis, Leathes 

 „ scalaris, Leathes 



Astarte Omalii, de Laj. 



„ triangularis, Mont. 

 Woodia digitaria, Linn. 

 Venus ovata, Penn. 

 Corbula gibba, Olivi 

 Dentalium entalis, Linn. 

 Cyprina islandica, Linn. 



These are all Coralline Crag shells and exceedingly abundant in 

 that formation. In addition, there have been found in these beds 

 35 species of mollusca, 11 of polyzoa, and 3 of echinodermata, 

 characteristic forms of the Coralline Crag. 



B. Erom beds regarded as Scaldisien. 



Cyprina islandica, Linn. 

 Venus ovata, Penn. 

 Mactra deaurata, Turt. 

 Corbula gibba, Olivi 

 Dentalium entalis, Linn. 

 Turritella terebra, Linn. 



,, incrassata, Sow. 

 Fusus gracilis, Da Costa 



„ contrarius, Linn. 



,, alveolatus, Sow. 

 Nassa reticosa, Sow. 



Anomia ephippium, Linn. 



Pecten opercularis, Linn. 

 „ similis, Laskey 

 „ ventilabram, Goldf. 



Mytilus edulis, Linn. 



Cardita chamceformis, Leathes 

 „ scalaris, Leathes 

 ,, orbicularis, Leathes 



Astarte Galeottii, Nyst 

 „ Omalii, de Laj. 



Woodia digitaria, Linn. 



Tellina comjoressa, Natica helicina, Nassa elegans, Fusus antiquus 

 (dextral), and Nucula Cobboldice, Bed Crag or Scaldisien, but not 

 Coralline Crag forms, are met with at this horizon; with one 



1 For convenience of reference I use the names adopted by Dr. Lorie. 



