THE PERCY SLADEN TRUST EXPEDITION. 103 
those from Funafuti, though more densely branching than the typical form as it appears 
at Funafuti and at the Maldives (cf. Fosl. Lithoth. in Gardiner, Mald. & Laccad. i. 
pl. 25. fig. 4)*. The species is probably more densely branched, the more exposed the 
locality is in which it is growing. Almost all the specimens collected are so far most 
nearly connected with f. congesta (cf. op. c. pl. 25. figs. 5, 6). Several of them, however, 
bear branches compressed or flabellate, for which reason they are to be referred to 
f. flabelliformis, though they are not wholly consistent with typical specimens of this 
form. Besides, some specimens approach much more to f. subtilis (cf. *Siboga' Exp. 
n. lxi. pl. 10. figs. 12, 13). Gon. frutescens thus proves to be a species varying 
much, like many other calcareous alge. This is no doubt partly due to local 
conditions. 
The alga appears to have grown in association with Lithoph. Gardineri, several 
of the specimens brought home having been accrete with that species or with corals. 
It probably occurs in large numbers, particularly at the Salomon Atoll and at Coetivy. 
At the former locality and at Egmont Atoll it seems for the most part to be sterile 
in the months of May and June, while some are richly fructifying at Coetivy in 
September, 
Localities. Chagos Archipelago; Salomon Atoll, reef; Egmont Atoll, reef and lagoon 
shoal; Coetivy, E. reef and other places (Stanley Gardiner). 
Area, The Maldives and Laccadives, and some places in the Pacific Ocean. 
Genus LITHOPHYLLUM, Phil. (emend.). 
Subgenus EuLrTHOPHYLLUM, Fosl. 
8. LITHOPHYLLUM OKAMURAI, Fosl. 
Five new Cale. Alg., in Kgl. Norske Vidensk. Selsk. Skrift. 1900, n. 3, p. 4. 
f. PTYCHOIDES, Fosl. 
Kgl. Norske Vidensk. Selsk. Skrift. 1906, n. 8 (1907), p. 29 (in Norwegian). 
This form is nearly connected with f. £rincomaliensis from Ceylon, but diverges from 
it by being less branching and by having partly smaller cells. The specimens are rather 
encumbered with extraneous objects and particularly much attacked by worms. In 
Consequence they are somewhat stunted and bear conceptacles sparsely. Also the 
Conceptacles have been attacked by organisms, and consequently sporangia are not to 
found. Conceptacles overgrown by new-formed tissue, on the other hand, occur in 
rather large numbers. | | me 
The forms hitherto known of Lithoph. Okamurai occur in the littoral region or in 
Shallow water, whereas f. ptychoides is found in a depth of about 26 fathoms. 
Locality. Saya de Malha, No. O 16 (26 fathoms), and No. C 19 (29 fathoms), uncertain 
(Stanley Gardiner). | 
Area. Ceylon, and several places in the Pacific. . 
a. Stanley Gardiner, ‘The Fauna kád Gicgriphy of the Maldive and Laccadive Archipelagoes,’ vol. i. part 4 
R 2 
