754 



SIR HENRY H. HOWORTH ON THE 



[Nov. 9, 



little further on our way and see how far the conclusion is borne 

 out b}' other facts in the history of this remarkable shell. The 

 question I would next ask is : Whence did Mya arenaria come 



Text-fiff. 238. 



Text-fio-. 239. 



Lateral and dorsal views of sliell of Mya truncata: from Prof. W. C. Brogger, 

 op. cit., bj' kind permission of the author. 



Text-%. 240. 



Lateral view of left shell of young Mi/a truncata ; from A. S. Jensen, in ' Vidensk. 

 Meddel. naturhist. Foren. i Kjobenhavn,' 1900, bj^ kind permission of the 

 author. 



when it invaded the Scandinavian seas ? There are two species 

 of Mya inhabiting the Scandinavian seas at present — M. arenaria 



