18 Mr. It. Kirkpatrick on 



Excellent figures of this species are given in Krauss's 

 memoir. The characteristic " ramis falcatis '' mentioned by 

 Krauss are a well-marked feature of the species, and enable 

 the distinction to be made from A. lendigera and from A. 

 Brongniartii, Desm. & Les. 



Krauss mentions that the internodes are much shorter than 

 in A. lendigera. 



AmatMa Wilsoni, n. sp. (PI. II. figs. 4, 4 a.) 



Zoarium formed of delicate, feathery, subcylindrical bunches 

 or festoons. Branching of main branches tripartite, tlu'ce 

 branches given off at each node, two laterally and one ])0ste- 

 riorly ; internodes partly occupied on anterior surface only by 

 from five to eight pairs of zooecia ; lateral and posterior 

 branches (z. e. those given otf at the nodes) branching pinnately, 

 with the biserial groups of zooecia on the upper surface, the last 

 two or three internodes unoccupied by zooecia (thus giving 

 the plumose appearance to the zoarium) ; one of the anterior 

 branches of each lateral branch much hypertrophied and witli 

 that of the opposite side forming an arch across the anterior 

 surface of a main branch (thus giving the festoons a some- 

 what cylindrical appearance). Dimensions of zooecia '5 

 by '14 millim. Stems whitish, thick, '4 to '5 millim. in 

 diameter. 



The system of branching of this beautiful species is highly 

 characteristic. In tlie collection of the Natural-History Mu- 

 seum there is a specimen from Port Jackson. 



AmatMa Brongniartn, Desm. & Les. (PI. II. figs. 3, 3 a.) 



Zoarium reddish brown, branched dichotomously ; inter- 

 nodes long, straight, occupied for nearly the whole length 

 (except '1 millim. at the lower end) by from ten to twelve pairs 

 of rather broad zooecia, '5 x "2 millim. Diameter of stems *! 

 to "lo millim. 



A. Brongniartii differs from A. hiseriata, Krauss, the 

 branching of which is also dichotomous, in the internodes being 

 straight, not curved (" ramis falcatis," Krauss), and in the 

 greater length of the internodes. The posterior aspect of ^. 

 Brongniartii shows the zooecia bulging beyond the stem on 

 each side. 



Through the kindness of Mr. Waters I have had the 

 opportunity of looking through certain unpublished plates, 

 engraved by Lesueur in 1829, in which arc figured '' poly- 

 piers flcxiblcs " collected in Australia. 



