253. 
vigorously collected. In the census given by him, 3606 species out 
of a total of 7865 belong to the Cryptogamia, which is a large 
proportion for a new country. 
With regard to the fungi and marine algae, though the founda- 
tions of the flora were worked out many years ago by Berkeley, 
ooke, Sonder and others, further supplies of material collected by 
Mr. Bailey and his collaborators have been continuously forwarded 
to Kew during the last few years. These have been determined as 
fully and rapidly as circumstances permitted, and the. names, many 
of which were listed at the time in the “ Queensland Agricultural 
Journal,” are now incorporated in the new catalogue. 
Amongst the algae forwarded several were set aside to await 
better material, or as worthy of more detailed notice. The 
following observations are the outcome of the investigation of some 
of this material. No corrections are put forward, nor are any 
additions to the catalogue recorded, the notes being for the most 
part of morphological or geographical interest. 
Ceratodictyon spongiosum, Zanard. 
Ceratodictyon is one of the most interesting of those marine algae 
at Dunk Island were forwarded. 
he symbiosis of the larger algae and sponges is not uncommon 
in the tropics, and the same phenomenon is met with on a smaller 
scale in the sponges of cooler regions. In the British Isles carpets, 
of short filamentous algae are often seen to be in competition with 
the encrusting sponges which grow in caves and other dar 
recesses on the shore. In some cases accidental concrescence of 
the two organisms is noticeable, in others such association is more 
or less constant and intimate. A further and much more advanced 
dominant partner, the sponge growing symbiotically on the surface 
of a large foliaceous thallus (see later). 
Ceratodictyon differs from all the above in that a change in form 
is probably induced through the commensal existence. The main 
segments of the thallus are composed of very slender multicellular 
branches, which are woven together to form a dense network, the 
are with little doubt materially modified in habit. Excellent 
latter are produced in special very short pedicellate lateral branches, 
and are oblong (60 x 25m) and cruciately divided, ! 
