86 M. FOSLIE. [1905 



under f. torosa, and without sporangia. The conceptacles of cysto- 

 carps resemble those of f. torosa. 



As to the synonymy it must be observed that when in Norw. 

 Lithoth. I referred f. torosa to Lithoth. glaciale, it was owing to 

 the conceptacles not normally developed. Besides the specimens 

 pictured 1. c, I then only knew a few others. The conceptacles 

 of this form, with their central parts but a little or faintly impressed, 

 are more nearly approaching the corresponding organs at a certain 

 stage of development in L. glaciale than typical conceptacles of 

 Ph. polymorphum. From the considerable material afterwards 

 collected it must be considered beyond doubt that f. torosa belongs 

 to the same series of forms as f. ocellata, and certainly also to the 

 same species. 



This species is nearly connected with Ph. polymorphum. I 

 have even had doubts whether it should not properly be regarded 

 only as a form of the said species. Particularly f. ocellata is 

 hardly distinguishable from certain forms of Ph. polymorphum, 

 principally such ones, occurring along the northern part of the 

 coast of Norway, in which new crusts frequently are covering 

 older ones. It is of no rare occurrence that Ph. polymorphum is 

 growing gregariously or even anastomosing with Lithoth. glaciale, 

 and, being attacked by animals, both species at an older stage 

 detach themselves from the substratum. In certain circumstances 

 also the part turning downwards of both the coalesced species is 

 covered by a new crust, which will bear a considerable resem- 

 blance to Ph. investiens f. ocellata. Also young crusts of Ph. 

 investiens on L. glaciale can be confounded with new crusts of 

 the latter attached to older ones. To this may be added — as I 

 mentioned under Ph. polymorphum — that along the northern 

 coast of Norway this species is often developing abnormal con- 

 ceptacles resembling the corresponding ones in Ph. investiens. The 

 form torosa, however, when most strongly defined, is much di- 

 verging and well marked. Besides, the species does not develop 

 excrescences or branches, which is generally the case with Ph. 

 polymorphum, and the conceptacles are mostly a little larger. 



Ph. investiens abounds in many places on the northern coast 



