lOO 



LAMELLIBRANCHIATA. 



A. Montagid van Warhami: 



Length 



Height 



The concentric ribs frequently reach right down to the ventral margin, but other specimens 

 are only ribbed on the umbonal region or to the middle of the shell, showing on the rest of the shell 

 only fine lines of growth (= Astarte fabula Reeve). 



Some few specimens belong to the variety striata, which in my opinion — as already mentioned — 

 is only a shorter form than ]Varliaini^)\ to try and keep them distinct owing to the different colour 

 of the periostracum is not correct, as the variety Warhaiiii. for example, may begin as straw-yellow 

 and end as dark-brown. — For the sake of comparison I may give here the measurements of the 

 few specimens from East Greenland : 



A. Montagu! var. striata: 



Length 



21-5 

 19 



17-5 



Height 



T»y r nini 



16 



14-5 - 



Height 



Breadth 



Only one specimen (from Hekla Havn) is so short in form, that it can be referred to the 

 typical Astartr Moiitagtii ; it has the following measttrements: 



This specimen also differs in its sculpture, the shell only showing fine lines of growth and 

 not the usual concentric ribs. 2). 



Jan Mayen. 



None of the Danish Expeditions have found it here, but it is stated to have been taken by 

 the Norwegian North-Atlantic Expedition as the variety globosa at a depth of 195 fm. (Friele) as also 

 by the Austrian Expedition at a depth of 105 fm. (Becher). 



9 The "Astartr Banksii Leach var. Warhami" of Posselt in his East Greenland Molluscs (I.e. 1895; PI. L f'gs- 3 -4) 

 has to be referred in my opinion to the variety striata owing to the relative shortness of the shell. 



-) It is this specimen which is figured by Posselt, I.e., figs. 1—2, under the name of Astarte Banksii Leach. 



