354 Tf. M. Bale: 



Aglaopiiknia BKACHiATA (Laiiiaick). 



Plumularia hrachiafa, Lamarck, An. s. Vert., ii., 1816, 



p. 126. Blainville, Man. d'Act., 1834, p. 478. 

 Agkiophtnia crucialis, Kirchenpauer, Abli. Nat. Ver. Hamb., 



v., 1872, p. 26, pi. i., fig. 8. Bale, Cat. Aust. Hyd. 



Zooph., 1884, p. 168, pi. xviii., fig. 8. 

 Thecocarjnis crucialiit, Billard, Ann. Sci. Nat. (9), v., 



1907, p. 328, figs. 3, 4. 

 Aglaoplicnia carinafa^ Bale, Proc. Boy, Soc. Vict. (N.S.), 



vi., 1893, p. 105, pi. vi., figs. 1.3. 

 Thecocarpus hi^achiatiis, Billard, C.R. Acad. d. Sci., cxlviii., 



1909, p. 1064; Idem, Ann. Sci. Nat. (9), ix., 1909, 



p. 331. 



My best specimen of this species is about 10 inches high by four 

 wide, and as each of the main branches has its minor branches in 

 the same plane the whole polypary forms a flattened frond. It is 

 very freely branched and rebranched from the base up. Another 

 specimen differs so much in genei-al appearance that without 

 microscopical examination it might be supposed a different species; 

 this is owing to its irregular and bushy habit, the branches being 

 much contorted and tangled-looking; it also has extremely short 

 hydrocladia. But I can find no difference in the form of the 

 hydrothecae or other minute structure. 



There is nothing specially noteworthy in the method of branch- 

 ing, such as might be inferred' from Lamarck's description, the 

 branches being given off mostly in pairs from two successive 

 internodes of the primary stem-tube, just as in the crucialis group, 

 and therefore taking the place of two hydrocladia. But they are 

 more numerous and closely set than I have observed them in A. 

 macrocarj)a and its allies, where they are usually more distant and 

 straggling. 



The corbulae seen are of similar type to those of the crucialis 

 group, closed, but having a series of openings at the bases of the 

 leaflets, over which project the lateral spurs given off from the 

 leaflets next behind. These spurs are stout but short, and for the 

 most part support only two receptacles, terminal in position ; the 

 inferior is a eonical sarcotheca, rather narrower than those on the 

 ribs, the superior, which projects rather beyond it, is mostly broader 

 and is considered by Billard to be a hydrotheca. It does not 

 appear so to me, and it is generally only about the middle of the 



