KUNGL. SV. VET. AKADEMIENS HANDLINGAB. BAND 39. N:o l. 9 
Here I will take the opportunity of giving expression to the pain and distress I 
have felt in placing them in that position, all the more as I thereby expose myself 
to the suspicion of courting the "”inevitable'" but, to my thinking, "distasteful” struggle 
for priority. "Inevitable", inasmuch as the fact of a man's being the first to discover 
a thing must be registered and "distasteful'; because such petty questions very fre- 
quently take up a great deal of the precious working-time of a scientific man, which 
he ought properly to be able to use to much better advantage. 
The chief object of this paper is to throw some more light upon the true Si- 
punculids. Considering that these animals have really very little to do with the sub- 
orders Priapulidea, Echiuridea, Saccosomatidea and the very problematic Epithetoso- 
matidea and, furthermore, that these in their turn do not present any very close 
relations among themselves, it may seem that they could properly be left out from 
this paper. For several reasons, however, I have thought that they may be suitably 
subjected to a brief discussion in a second paper. An enumeration of their respective 
species as occurring in the northern and arctic seas together with geographical notes 
upon them may be of interest. 
Critigue of the Genera of Sipunculids hitherto known to inhabit the 
Northern and Arctic Seas. 
A synopsis of the six northern genera of the sub-order Sipunculacea is given 
below: — 
A. The longitudinal muscles of the wall of the trunk separated in bands. 
a. Tentaeles numerous, digitiform or filiform, arranged in a circle, 
open backwards and situated above the mouth. . . . . . Physcosoma 
b. Tentacles arranged in a cirele round the mouth. . . - - . Sipunculus 
B. The longitudinal museles of the wall of the trunk, forming a conti- 
nuous layer without bands (except in some exotic forms of Aspi- 
dosiphon). 
a. Anus normal in the anterior part of the trunk. 
I. Intestinal tube forming a spiral, stretching along through 
the body-cavity often with a spindle-muscle. Retractors, 2 
dorsal and 2 ventral or only 2 ventral. Segmental organs 2. 
" priority at their expense; I have given it merely for the sake of making known the true state of the case 
and in order to rescue the papers referred to from falling into total oblivion. 
If SELENKA had not overlooked the papers referred to, his anatomical review would, it is fair to allege, 
have gained in value as regards, for instance, the segmental organs, the genital organs etc. The question 
would, indeed, be an immaterial one, if it could be taken for granted that KOorREN and DANIELSSEN are right 
in their anatomical investigations, as SELENKA seems to have imagined. <Considering that all the four papers 
were er in the same year 1875, it may fairly be considered to have been SELENKA'S bounded duty to 
cite them all, 
