312 'ENDEAVOUR" SCIENTIFIC RESULTS. 



many cases there is a distinct interval between them. The 

 intrathecal ridge is generally very narrow. 



The mesial sarcotheca may be nearly straight, or slightly 

 arched, and stands off at a wide angle from the hydrotheca, 

 which it somewhat exceeds in length. The increase in size 

 of the lateral sarcothecae on the last internode or two of a 

 ihydrocladium is more marked than I have seen it in any 

 other species, and it is not rare to find those on a terminal 

 internode almost equalling in diameter the hydrotheca itself, 

 while the next hydrocladium may be normal throughout. 



The corbulae are similar to those of A. acanthocarpa, Allman, 

 but the bifid condition of the first unpaired sarcotheca on 

 -each pinnule is by no means invariable. These corbulae 

 resemble those of A. plumosa, Bale (a species not otherwise 

 closely related to the present), but the pinnules in A. plumosa 

 .are less arched, the corbula being somewhat compressed. 



Locs. Oyster Bay, Tasmania, 60 fathoms. 



Twenty miles east of King Island, Bass Strait. 



Fifty miles south of Cape Wiles, South Australia, 75 fathoms. 



Sanders Bank, Kangaroo Island, South Australia, 28 

 fathoms. 



Forty miles west of Kingston, South Australia, 30 fathoms. 

 Hunter Group, Bass Strait. 



AGLAOPHENIA DIVARICATA (Busk), var. MCCOYI, Bale. 



Aglaophenia McCoyi, Bale, Journ. Micro. Soc. Viet., ii., 1881, 

 pp. 36, 46, pi. xiv., fig. 2. 



Aglaophenia divaricata, Bale, (in part), Cat. Austr. Hydr. 

 Zooph., 1884, p. 162, pi. xv., fig. 7, pi. xviii., fig. 6. 



Hydrophyton smaller than in the type ; hydrothecae with a 

 wide intrathecal ridge, the anterior tooth furnished with a 

 delicate erect crest ; mesial sarcotheca with the distal portion 

 erect and widened at the summit in a crescentic form. 



Corbulae as in the type. 



In the " Catalogue " I united A. mccoyi with A. divaricata, 

 as I found that certain specimens of the latter appeared to be 

 transition forms. The specimens in question, however, 

 though approximating to A. mccoyi in the broad mesial 

 sarcothecae, undoubtedly belonged to A. divaricata, and I 

 have not so far met with other intermediate forms. There 

 seems, therefore, sufficient ground to treat A. mccoyi as at 

 least a distinct variety. 



