132 THE VOYAGE OF H.M.S. CHALLENGER. 
instead of being derived from them. This indeed seems borne out by the structure of 
the corallum of the very young forms which are still attached to the nurse-stock. In 
these the walls are well developed and almost imperforate, while the synapticul are 
comparatively undeveloped. Additional evidence for this view can also be drawn from 
the relation of the synapticulee to the wall in many forms of the Cycloseride and Plesio- 
fungidee, in which, while it is convenient and is customary to speak of the walls of the 
smaller developing calicles as being formed by the upgrowth, the increase in size, and 
the fusion of the synapticulee (as though these structures were distinct from the wall in 
their origin), it must be remarked that the synapticulz appear to be direct interseptal out- 
growths of the wall (as in Agaricia, Tichoseris, Domoseris, &c.); so that the statement 
that the walls are synapticulate, or that the walls are formed by the fusion of synapticule, 
would appear to mean nothing more than that the different parts of the wall which are 
deposited separately (and are then called synapticule) enlarge during growth and fuse to 
form a solid, more or less continuous mass, which is the more commonly known “ wall.” 
Tt must be confessed, however, that conclusions as to the relations of these parts are 
practically but guesses at the truth of the matter; proofs of such relations in this, as in 
so very large a number of other cases among the Corals, can only be obtained when the 
development of these different structures from the soft parts in the young forms have 
been thoroughly investigated. 
A remarkable degree of variation seems to characterise the different forms of Fungia, 
as is well evidenced by specimens in the collection; and our knowledge of constant 
specific characteristics and limitations, if such indeed exist, is very imperfect in these as 
well as in the other Reef-Corals. 
From their great size and weight, and their unattached condition, the species of 
Fungia offer apparently the most suitable examples on which continuous and detailed 
observation and experiment may be made ; while their remarkable abundance and peculi- 
arly favourable position on the reefs at Banda and Tahiti would seem to point to such 
localities as being the best adapted to such investigation. It is certainly a promising field 
for any naturalist who, with time and means at his disposal, would devote himself to it. 
Thirteen species of this genus are in the collection. 
1. Fungia patella (Ellis and Solander). 
Madrepora patella, Ellis and Solander, Zoophytes, p. 148, pl. xxviii. figs. 1, 2, 3, 4. 
Fungia agariciformis, Leuckart, De Zooph. Corall., p. 42, pl. iv. figs. 1-4. 
»  agariciformis, Dana, Zoophytes, p. 292, pl. xviii. figs. 5, 6. 
patella, Milne-Edwards and Haime, Cor., iii. p. 8. 
patella, Klunzinger, Cor. roth, Meer., p. 61, pl. vii. fig. 4, and pl. viii. fig. 2. 
bP 
” 
Some very large and two small specimens of a variety of this common species were 
obtained. The septa are very thin at the upper border, with very small teeth. The 
