2 ARKIV FÖR ZOOLOGI. BAI^^D 7. N:0 4. 



first time/ were brought together by O. Torell during a 

 dredging-excursion to Iceland in 1857. They are derived to 

 a great extent from the northern parts of Iceland, being 

 therefore of interest, as these coasts are tlie ones least ex- 

 plored. But the collections are interesting in another respect 

 also. They form the basis of jEFrREY's accounts in »British 

 Conchology» on occurrences of British species off Iceland. The 

 collections were, according to Mörch (1869), in London and 

 were there seen by Jeffreys. The species mentioned by him 

 will be especially noticed in the following. Besides Jeffreys, 

 Torell mentiones (1859) the occurrence of some species off 

 Iceland; these statements also have been referred to in the text. 



The present account is essentially a catalogue of the 

 species procured with statements of their occurrence. In order 

 to increase the value of these statements I have given for every 

 locality the maximal measurements in millimeters of the spe- 

 cies as a good exponent of the favourability of the biological 

 circumstances of the place, for it may be a rule that a greater 

 size indicates more favourable conditions of life for the animals. 



The situation of the localities mentioned above is evident 

 from this survey: 



Arnanes in the NW peninsula; 

 Berufjord and B j arnanes on the SE coast; 

 Hofsos on the S coast W off Vatna Jökul; 

 Raufarhofn at Thistilfjord, NE coast; 

 Reykiavik on the SW coast; 

 Siglafjord on the central N coast; 

 Thistilfjord in the NE corner of Iceland; 

 Öfjord on the central N coast. 



As a summary a tabular survey of the species and their 

 distribution is given and afterwards some general remarks 

 about the fauna with an attempt at explaining the differences 

 in its composition in some localities. 



In conclusion it rests with me to express my gratitude 

 to prof. Hj. Théel for his kindness in placing the collections 

 at my disposal and making it possible for me to describe 

 them. 



^ The Opisthobranchia were published by the aiithor in 1907; they 

 are included, with some additions, in the present catalogue. 



