242 
TLYANTHID^. 
form. The manner in which the mouth is represented as 
pm'sed out, and closely investing the gonidial tube, with 
the gular furrows looking like rudimentary tentacles, I 
have observed both in this and the foregoing species. 
P. Boeckii is assigned to a depth of 80 to 200 fathoms in 
the fjords of Norway. 
The posterior orifice in this genus cannot always be 
observed; I have, however, satisfactorily demonstrated it 
by dissection in both hastata and undata. When the inte- 
gument is cut away from the whole vicinity, it appears as 
a circular foramen, about half a line in diameter. It does 
not appear to be an anus, but probably admits water for 
respiration. 
The specific name, undata, indicates the waved pattern 
of colouring on the tentacles. The term Muzzlet, which 
I have assigned to the genus, alludes to its most prominent 
characteristic, — the protrusion of the gonidial tube, like a 
proboscis or muzzle. 
hastata. 
triphylla. 
UNDATA. 
