Praeger — On the Raised Beaches of N.E. Ireland. 45 



glacial clays has been used in preference to boulder-clays, since the fine 

 clay, often without boulders, which has been already referred to, has 

 yielded more fossils than the boulder-clay proper. The placing of the 

 raised beaches after the estuarine clays, is not intended to signify neces- 

 sarily a stratigraphical relation ; but it may be assumed, with tolerable 

 certainty, that the raised beaches are in no case older than the clays. 



N represents a species of Arctic distribution, not now living in the 

 British area. IS" represents a species, whose present distribution 

 ranges from Britain northward only : most of these have their head- 

 quarters on the Scandinavian shores. S represents a species whose 

 present distribution ranges from Britain southward only : most of 

 these have their headquarters in the Mediterranean. 

















o 













•Ti 





o 









^ 





.9 



• 



iC 



: Species. 



^ 



^ 









.2 ^ 





r^ 



03 c3 



■*-* ri 



•r-) Ci 







cS 





m ^ 



cj CD 



"y, c3 





pq 



33 



Wo 



PhW 



P^Pm 



Rhynclionella psittacea, 





N 



— 



— 



— 



— 



Mytilus modiolus. 





— 



— 





N 



N 



Pinna rudis, 





— 



— 







— 



S 



Crenella decussata, . . 





— 



— 



N 



— 



IT 



Leda pernula, . . . , ' . 





N 



n- 



— 



— 



— 



Area lactea, . , , . 





— 



s 



— 



s 



— 



Astarte elliptica, ., .. ' . 





N 



N 



— 



— 



— 



A. compressa and var. globosa, ' . 





liT 



N 



— 



— 



— 



A. borealis, 





N 



N 



— 



— 



— 



Yenus verrucosa, 





— 



— 



— 



s 



— 



Venerupis irus, 





— 



— 



— 



s 



— 



Tapes decussatus, . . . , 





— 



S 



S 



s 



— 



Tellina calcarea, 





N 



N 



— 



— 



— 



T. donacina, ,. ., 





— 















s 



Gastrana fragilis, 





— 



— ' 



s 



— 



— 



Lutraria obtonga, 





— 



— 



s 



— 



— 



Thracia pubescens, . , 





— 



— 



s 



— 



— 



Gastrocbaena dubia, . . 





—1 







s 



_ 







Pholas parva. 





S 



— 



- 



— 



— 



