128 Rev. T. Hincks on Norwegian 



capsules, instead of being borne, as in A. radicellata^ on a 

 certain number of the pinnules which are modified in structure 

 so as to constitute a protective case for them (the corhula)^ are 

 ranged along one side of the main stem ; the usual corbula is 

 absent; but at the base of many of the pinnules a bifid or 

 trifid process is developed, and these processes, ranged 

 in a row on each side close to the stem, bend inwards 

 towards one another and so form a kind of protective co- 

 vering for the gonothecae. This structure is unique amongst 

 the known Plumulariidge. The processes just described are 

 furnished with many of the sarcothecse (or nematophores) so 

 characteristic of the Plumularian family, and closely resemble 

 in structure the elements which compose the corbula. Indeed 

 we may regard them as constituting a kind of corbula, which, 

 however, is developed in the axis of the plume, con-esponding 

 with the altered position of the capsules, instead of laterally 

 along the pinnule. A. bicuspis fixes itself upon sponges ; and 

 its fibrous base is merely a flattened disk for attachment. 



In the third species {A. Integra), which is of larger growth, 

 of a graceful plumose shape, and occasionally branched, we 

 have the very same type of calycle ; but the tooth-like processes 

 on the margin have disappeared as well as the crenulation, and 

 the rim is now perfectly plain. The sarcothecse are much the 

 same as in the two preceding forms ; the capsules are borne 

 on the central stem, as in the last, but all traces of protective 

 appendages are wanting. The gonosome exhibits the character 

 which we find in A. pennatida and kindred species. 



From this deep-water region, then, near Hvitingso we have 

 three species of Aglaophenia all referable to the myriophylluni 

 type, which are distinguished by very slight differences in the 

 minute structure of the trophosome, but exhibit three distinct 

 modifications of the gonosome. In the one which comes nearest 

 to A. myriophyllum we find the usual open corhula ; in another, 

 a set of appendages developed near the base of the pinnae, 

 constituting a kind of axial corhula ; in the third we have the 

 gonothecae wholly unprotected, as amongst the Sertulariid^e, 

 and borne on the main stem. The first of these modifications 

 of the gonosome is characteristic of Kirchenpauer's subgenus 

 Lytocarpia, and the second, I believe, of Allman's genus 

 Gonocladium (to be described in the report on the 'Porcupine' 

 dredgings). If the genus Aglaophenia is to be dismembered, 

 and the species composing it are to be distributed into groups 

 distinguished by the character of the gonosome, I should pro- 

 pose the name Gymnangium for those with unprotected 

 gonothecffi. 



Sars has also added to the Norwegian list several species of 



