28 



HYDROIDA 



one individual to another in a larger colony, and individuals with quite smooth stems are not seldom 

 observed in colonies which are otherwise typical Tubularia larynx. The dimensions of Tubularia humilis 

 wholly agree with those of young colonies of Tubularia larynx, and the numbers stated as characteristics 

 stand far within the range of variability known in this species. Then only remains the condition of 

 the blastostyles, which should be erect in T^lbularia humitis, but hanging in Tubularia larynx. An 

 examination, however, of living material will show that only in rare cases the blastostyles of Tubtilaria 

 larynx can be described as hanging (comp. Broch 1911); on the contrary they are generally borne in a 

 rather erect position, particularly when not yet very large. Thus also this criterion proves to fail, 

 and consequently we are forced to consider Tubularia humilis as a synonyme of Tiibularia larynx. 



Tubularia larynx is an entirely boreal species, which has its main occurrence in the zone of the 



60 



200 m. fr oo m. 



Text-fig. F. The distribution of 



. _._.looo m. looam. 



Tubularia larynx in the Northern Atlantic. 



laminaria and the red algae. Towards the south it enters into the Mediterranean, and towards the 

 north it penetrates as far as Nova Zembla, and seems still to occur at Spitsbergen. On the south- 

 western coasts of Iceland it is very frequent, and it is also found on the east coast of North America. 

 It is to be wondered that the species has not yet been met with at Greenland. 



Tubularia sp. indet. 



Stems of Tubularia of the type indivisa-regalis are in hand from the following localities: 

 "Ingolf" St. 8. 6356' N., 2^40' W., depth 136 fathoms, + 6o C. 

 - 35- 6 5 i6' - 55 o 5 ' - 362 + 3% - 



- - 36. 6i 5 o' - 5 62i' - - 1435 - + i5 - 



