242 ilyanthidjs. 



form. The manner in which the mouth is represented as 

 pursed 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. Boechii 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 Jiastata 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. 



