20 THÉEEL, NORTHERN AND ARCIIC INVERTEBRATES. I. SIPUNCULIDS. 
Account of the Species. 
Physcosoma Lovénii (KOREN and DANIELSSEN) SELENKA 1883 & 1897. 
Pl: VILI Bigs: 1205-1275; PII IX) Pigs) 128 1365 PI XM) bigst 2100-2127 
Phascolosoma Lovenit IKOREN and DANIELSSEN. 1875 and 1877. 
Habitat: 
West Coast of Norway: Bergen Fjord, at a dept of 50 fathoms; stony bottom, 
only one specimen. (Mus. B.). 
I have had the opportunity of examining the single specimen hitherto known 
of this highly interesting form, but unfortunately it is tattered to such a degree as 
to make an exact inspection of it impossible. Consequently, I am restricted to refer- 
ring to the description of its two discovers, KOREN and DANIELSSEN, though I have 
reason to believe that several of their statements are incorrect, and further, to my 
own figures of the tentacles and of the corpuscles of the skin in place of theirs, 
which were not quite satisfactorily drawn. 
The description and figures by KOREN and DANIELSSEN give a wrong idea of 
the anterior portion of the animal in question. However, on account of its unsatis- 
factory state of preservation, it is impossible to give a correct true figure of the whole 
animal, or to make a true copy of its anterior portion. The tentacles (Figs. 110—112) 
are 32 in number, have a more or less cylindrical shape, and form above the mouth 
a dorsal crown, which posteriorly is not complete, for at this point in the middle, 
the crown passes into a fold, which bends over so as to embrace the mouth-disk. 
Thus the fold in question, itself devoid of tentacles, passes into the tentacle- 
crown forming a ring, open posteriorly. Within the tentacle-erown and close to the 
place where it is broken in outline, that is to say outside the brain, there is to be 
observed a structure (Figs. 210—211 c s), the true shape of which is impossible to 
make out on the fragmentary specimen at my disposal. It may have been double, 
the left portion having been detached. It evidently corresponds to the ciliated sense- 
pads found in the Phascolosoma-forms. i 
Behind the tentacles and the tentacular fold a smooth zone is to be seen, 
limited posteriorly by an annular collar, which totally escaped the attention of 
KOREN and DANIELSSEN. They also overlooked the presence of numerous rows 
or rings of hooks behind the collar. I have not been able to count the exact 
number of hook-rings, but certainly there are not less than sixty of them. The hooks 
(Figs. 129—136) are triangular, more or less curved and compressed, and with a long, 
nearly straight, base. In the rings situated in the front, the hooks attain their 
greatest dimensions. Omwing to the fact that the whole specimen is very defective, 
and that most of the hooks are broken off, I cannot ascertain whether the "Quer- 
runzeln" are present or not, As to the origin of the hooks, it seems to have been 
