LAMELLIBRANCHIATA. 



103 



By far the great majority of the WV-.st Icelandic specimens belong to the typical A. Montagui 1 ). 

 Thus, all the specimens from the southern part of the west coast belong to the typical form, 

 as will be seen from the following examples: 



. Height Breadth 



Locality Length Height Breadth 



Length I.e: 



Grundarfjordr 18.3 mm . 17 """. 92.9 10 



17 - 157 - 924 - 9 52-9 ■ 



Engey 17.2 - 15.8 - 91.9 46.5 - 



Hafnarfjordr 17.2 - 16 - 93 - 10 58.] 



16.5 - 15.8 - 95.8 - 10 - 



E. N. E. of Helganes 13.5 - 13 - 96.3 - 7.5 ■ 55.6 - 



Keflavik 14 - 13 - 92.9 - 7-5 - 53- 6 



The typical A. Montagui also occurs on the northern part of the west coast, but by side of 

 it we find moreover somewhat more elongated specimens, which approach to or may be entirely re- 

 ferred to the variety striata; this is seen from the following measurements: 



Height idth 



Locality Length Height Breadth 



Length Length 



Talknafjordr 18.2 16 87.9' 9 m ". 4 l )-4 



16.8 - 15.2 - 90.5 - 8.5 - 50.6 - 



15 " J 4 - 93-3 - 53-3 ■ 



Patreksfjcirdr 19 - 16.5 - 86.8 - 



17 - i5- 2 " Sl >-4 - 8 -75" 5 x -5 " 



15-7 - r 4 - §9-2 - 8 - 5 1 



14 - 13 " 92-8 - 7-5 - 53- 6 - 



South Iceland: 



Vestmannaeyjar 30 fm., gravel. 5 valves. 



— 49 - , clay with a little mud. 1 spec, cv 40 valves. 



63°24' N. E, i7°5 r W.L, 70 - 2 valve-. 



The maximum length of these specimens, which belong to the typical A. Montagui, is i| 



Faeroes. 



Here the species is common at depths of ca. 5— 50 fm. The maximum length is [9.8 



The various localities are as follows: 



Viderejde 10 fm. ' spec. 



Klaksvig 10 — is - r 



& 7 



■) A specimen from Grundarfjordr is even so high and short, with the posterior margin sloping so steeply, that n 

 resembles the form figured by Brown under the name of Crassina obliqvn (lllustr. Conchol. Great Britain and Ireland, I 

 PI. iS, fig.6), but in the second edition of his work given as a varietv of i (lllustr Rev. Conchol. Gr. Britain 



and Ireland, i.S|], p. 96, PI. 38, fig.6) Us measurements are as follows: height [7.5 mm -. length 17.5 >»'»., breadth 

 This characteristic loon also occurs at the Fseroes. 



