6 NILS ODHNER, NORTHERN AND ARCTIC INVERTEBRATES. III. OPISTHOBBANCHIA ETC. 



The figures drawn in colours will undoubtedly be a help in the study of this 

 paper. They belong to a coUection. which Lovék had made for the purpose of 

 prospective reproduction. ' They were painted by the two celebrated artists, F. and 

 W. v. Wright, and serve to complete in certain respects Lovén's »Index Mollus- 

 corum Scandinaviee » , which has hitherto been almost the only source whence a know- 

 ledge was obtainable of the maiine molluscan fauna found off the Swedish west-coast ; 

 to this work several figures a] so ref er which Loven has numbered himself. Only a 

 few of the figures were foUowed by measurements stating the natural size; these 

 are retained here as they appeared, and the omissions must be filled in from the 

 statements of length in the systematic section of the present paper. 



The figures could not be arranged in systematic order, for the exigencies of 

 printing have necessitated the colour tone being considered in the first place. 



The neAv specimens which are found in the coUections are figured on Plate I. 

 For want of space four figures also have been printed in the text. The descriptions 

 of the new forms are brought together particularly in the end of the report. 



Now there only remains for me to express my gratefulness to those, who have 

 aided me in my labours, especially to Professor Hj. Théel, who has kindly placed 

 the collections at my disposal, aided me by the loan of literature and with invalu- 

 able advice, and to Mr. G. Liljevall, who has drawn and put together the plates 

 with his well-known ability. 



^ Compare the extract from a letter to Berzelius, cited by Professur Théel in »Sven Ludvig Lovéii'. 

 (Lefnadsteckn. öfver K. Sv. Vet. Akad;s ledamöter Bd. 4 H. .3 sid. 48). 



