FORTALE. 



PREFACE. 



Næi'værende Værk, til hvis Udgivelse Staten 

 liar bevilget de fornødne Midler, blev paabegyndt 

 for mere end et Decennium siden; men forskjellige 

 nforudseede Omstændigheder har bevirket, at Ud- 

 arbeidelsen af samme i længere Tid har maattet 

 standses, saa at forst nu Værket kan udkomme i 

 sin Helhed. Oprindelig var Bevillingen givet til 

 den fortsatte Udgivelse af Fauna littoralis Norvegice, 

 hvoraf tidligere er udkommet 3 Bind, forfattede 

 dels af min Fader alene, dels af ham i Forening 

 med nvi afdode Overlæge Danielssen og Konservator 

 Koren. Da det forekom mig, at denne Titel paa en 

 mindre heldig Maade vikle komme til at begrændse 

 Stoffet, tillod jeg mig at foreslaa, at Benævnelsen 

 littoralis udgik og at Værket herefter skulde ud- 

 komme under den her anvendte Titel. Det af mig 

 til nærværende Bind valgte Stof er ogsaa af den 

 Art, at det vanskeligt vilde passe indenfor Eammen 

 af den tidligere Titel, da jo her ikke blot Sødyr, 

 men ogsaa en Del ægte Ferskvandsdyr er omhand- 

 lede. Idethele syntes mig, at den mere omfattende 

 Titel, Fauna Norveqiæ, bedre maatte kunne svare 

 til sin Hensigt, da der herunder vil kunne leveres 

 Bidrag til Belysning af hvilkensomhelst Branche af 

 vor Fauna, der maatte frembyde en særlig Interesse. 

 I Overensstemmelse med de 3 udkomne Bind af 

 Fauna littoralis, tror jeg at nærværende Værk bør 

 indeholde Afhandlinger af en mere iidforlig ana- 

 tomisk-biologisk Chai-acter, behandlende visse ud- 

 valgte Dele af vor Fauna og udstyrede paa en saa- 

 vidt muligt tidsmæssig Maade, saavel hvad Text 

 som Plancher angaar. I et andet, paa engelsk skre- 

 vet Værk har jeg paabegyndt en Bearbeidelse af 

 vor Fauna efter et herfra temmelig f orskjelligtPrin- 

 fip, idet dette Værk er nærme.st beregnet paa at 



The present work, for the publication of which 

 the Government has granted the necessary funds, 

 was begun more than ten years ago; but various 

 unforeseen circumstances having combined to jjut a 

 stop to the preparation of the work for a considerable 

 time, it is only now that it can be publLshed in its 

 entirety. The grant was originally given for the 

 continued publication of Fauna littoralis Norvegice, 

 of which three volumes had already been published, 

 written partly by my father alone, partly by 

 him in conjunction with the late Dr. Danielssen, 

 and Cui-ator Koren. As it seemed to me that this 

 title would limit the subject-matter somewhat 

 infelicitously, I ventured to .siiggest that the desig- 

 nation littoralis should be struck out, and that the 

 work should hereafter apjjear under the title here 

 employed. The matter chosen bj^ me for the pre- 

 sent volume, is also of such a kind, that it could 

 hardly be included under the former title, as not 

 only marine animals, but also some true fresh-water 

 animals are here treated of. Upon the whole, it 

 seemed to me that the more comprehensive title. 

 Fauna Norvegice, would better answer its purpose, as 

 under it, contributions might be made to the infor- 

 mation concerning any branch of our fauna that 

 might offer special interest. In accordance with the 

 3 published volumes of Fauna littoralis, I think that 

 the present work shoixld contain treatises of a more 

 exhaitstive anatomical-biological character, dealing 

 with certain parts of our fauna, and got up as 

 far as possible in a manner suitable to the times, 

 as regards text and plates. In another wox'k, 

 written in English, I have begun an account of our 

 fauna on a very different principle to this, as it is 

 rather calcixlated to give, as far as possible, a brief, 



