irVOROIDS BRIOGR. 41 



Nomenclature. — Dyvamend (Micjini, Laiiionroiix, is said by Billard, 

 who has examined the type, to be identical with the variety described by 

 him in 1907 as I'usi/thea ijiutdn'dentata, var. haJei. I, thei-efore, use 

 Lamouroux' name iov this variety. 



Loc. — Growing on a seaweed thi^own up on tlie sandy beach of the 

 lagoon, Lord Howe Island. 



Distribution. — This variety lias hitherto been recorded only from 

 the following localities: — Australia (Lamotii'oax) ; Boudi, New South 

 Wales (Bale) ; Mozambique (Billai'd). 



Family PLUMULARID^. 



Genus Plumdlaria, Lamarck. 



Plumularia balei, Bartlett. 



(Plate v., tigs. 8-10.) 



Pliimvlaria halei, Bai'tlett, Geelong Naturalist (2), iii., 4, li)07, p. 65, 



tigure. Id., Mulder and Trebilcock, Jhid. (2), iv., 1, 1909, p. 29, 



pi. i., figs, l-o (not PlumidariK b(dei, Billard, Arch, de Zool. exp. et 



gen. (5), viii., 1911, p. Ixiii., fig. 8). 

 Piiimularid, sp. nov., Whitelegge in Etheridge, Mem. Austr. Mus., ii., 



1889, p. 41. 



Trophosome. — Hydrophyton reaching a height of 6 mm., mono- 

 siphonic, unbranclied, bearing hydrothecae as well as hydrocladia. The 

 lower portion of the stem consists of a varying number of inteinodes 

 separated by transverse joints, the lower internodes being destitute of 

 appendages, while those nearest the cladate portion of the stem bear a 

 series of several sarcothecfe. The lattei' internodes are separated by an 

 ax'ticulation very oblique iii lateral view, and resembling from the front 

 two cones, the points of which interpenetrate. The hydrocladia are 

 alternate, each borne towards the distal extremity of an internode. They 

 spring fi'om one side or the other of each stem-hj^drotheca, and are 

 divided into alternatel}^ long and short internodes, of which only the 

 former bear hydrothecee. 



The hydrothecae lie almost parallel with the hj'drocladium in their 

 proximal portion, while the distal part is curved outwards. The fi'ont 

 wall of the hydrotheca is deeply inflected at about its middle. There is 

 a well-developed anterior intrathecal ridge proceeding from about the 

 middle of the front of the cell, and extending a little more than half-waj' 

 across the cavity. The border of the hydrotheca is undulate, peaked 

 behind and in front, and with a small lateral tooth-like projection 

 opposite the peduncle of the supi'acalycine sarcotheea. The back is free. 



The sarcotheea? are bithalamic, canaliculate ; one in front of each 

 hydr»theca, fixed, curved over and almost appressed to the hydrotheca ; 

 one slightly smaller, fixed, between every two hydrothecae, on the 

 intermediate internode; one, fixed, in the sinus behind the back of each 

 hydrotheca; and one at each side of a hydrotheca borne on a long 

 slender, tubular peduncle, and projecting beyond the boi'der of the 

 hydrotheca. These supracalycine sarcothecfe have the whole of one 

 side open. 



Gonosome not observed. Tbe gonangia aie described by Mulder and 

 Trebilcock as " Gonothecae — male, ovate slightly longer than hydrothecje, 



