KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 39. N:0 |. 75 
too, to which the animal are subjected, have decided me in taking this view. Thus, 
for instance, I cannot imagine that a species, fitted for a life at a trifling depth in 
the warm water of the Bohuslän Archipelago, hidden among the sandy tubes of 
Sabellaria, and dependent on them, can also be found living freely on a clay bottom 
in the cold water at great dephts in the Arctic Sea. Notwithstanding the most 
striking resemblance, my conviction is that they ought to be looked on as distinct 
forms, and that a repeated, minute investigation will reveale some, may be inconsi- 
derable, distinguishing characters. In short, if doubt prevails with regard to the 
identity of species, my belief is that it causes less confusion to keep the doubtful 
species separate than to combine them. It will be found in the following discussion 
of the relations between the above species, that my statements differ in several re- 
spects from those of IKOREN and DANIELSSEN; this depends on the fact, that I have 
had at my disposal for inspection some of their own type-specimens, which has en- 
abled me to correct their statements in certain particulars. 
If we first of all take into consideration the respective proportions between 
the proboseis and the trunk itself, as far as they can be made out, the annexed 
table may give a tolerably good idea of them. 
= CS 
| H 25 = Sens v | 
I 5 or eRed 5 | | 
EN eb ORSIRLS | 
-—9 I 5 eo Gr RR js 12) I 
= OK I SALE Oj 3 
fa il : ARS 
Well defined or questionabhle Hl IN So T3SR Notes | 
species SE 8 2 vc | G | 
SE | ARR FE | 
sr 3 ör TRA vn | I 
- : [>] 
= Leo Mer 
| SR SS S3R 8 
| => | SN SN 
T 
- Se 
Bb Kay SSORLDN er td selon LES | 38 mm. 11 mm. | less than '/3 
Ph. Lilijeborgii | 74 mm. SU ma | Ha 
l2 
I 
Ph. glaciale | 51 mm. 26 mm. | more than '/2 | According to DANIELSSEN and KOREN the 
| proboscis is twice as long as the »trunk». 
RR Narsi ts få ol Re diersslas | 10 mm. 3 mm. | less than '; | According to DAN. and KOREN the proboscis 
| I : S 
I I is a fourth of the »trunk». 
Fan CO PSRU SER dä. en BR Sr ma 2255 Dam tjo 
I 
| 
IPRS INR DOLLAR MN äfe es st NT FST MIM FAS ANNE | Ya 
| 
Ph improvisum Nn: -: so sd cc 15 mm. 7 mm. | less than ' | Length of the proboscis variable, but in most 
| cases always greater than in Ph. Sabhel- 
| | larie, 
From the above -comparison it is evidently not possible to draw any extensive 
conclusions, at the most, that the proboscis is comparatively speaking longest in 
Ph. glaciale and shortest in Ph. Sarsi. The proportions between the length of the 
proboscis and that of the remaining part of the body do not certainly give any true 
expression for the relationship of the species in question, at least not when the 
measurements are based on specimens preserved in alcohol. 
If, on the contrary, one takes into consideration the shape of the tentacular crowns, 
two groups could be distinguished, one with tolerably well-developed tentacles, and 
the other with tentacles reduced to some minute, irregularly rounded protrusions 
of the oral disk. I have not myself had the opportunity of examining more in de- 
