GEPP—MARINE ALG AND MARINE PHANEROGAMS. 391 
f. platydisca, Hi. 8. Bart., Amirante, below 20 and 25 fms. Seychelles, below 34 and 
44 fms. Saya de Malha, 26 fms. Cargados Carajos, 30, 45, and 47 fms. 
Geogr. Distr. Mediterranean. Atlantic. Indian Ocean. Pacific. 
32. Halimeda cwneata, Hering, in Flora, xxix. (1846) p. 214; E. 8S. Bart. Siboga- 
Expeditie, Mon. lx. Halimeda, p. 15, t. 1. 
f. undulata, H.S8. Bart., Chagos Archipelago: Coin, Peros, and Salomon, on reefs 
exposed at dead low tides. 
Geogr. Distr. Indian Ocean. Pacific. 
These specimens have the habit of f. wndulata, with the undulate and thickened 
margin, and have also the thickened junction of filaments at the apex of each joint, 
but the lateral walls of the peripheral cells are not connected for more than a quarter 
of their length, and in some cases hardly so much. 
33. H. Opuntia, Lamour. J. c. p. 186; E. 8. Bart. 1. c. p. 18, t. 2. 
f. typica, E.S. Bart., Amirante, below 20 fms., below 25 fms., 30-100 fms. Seychelles, 
34 fms. Saya de Malha, 25, 26, 29, and 55 fms. Cargados Carajos, 30 fms. Chagos 
Archipelago: Salomon reef, Coin, Peros reef, Chagos 30 fms., Diego Garcia reef. 
f. typica, H. 8. Bart., varying to cordata, HK. 8. Bart., Amirante, 25 fms. Cargados 
Carajos, 30 fms. Chagos Archipelago: Salomon reef. 
f. ty pica, E. 8. Bart., verging to ¢riloba, H. S. Bart., Salomon reef. 
f. typica, verging to cordata and triloba, Diego Garcia reef. 
f. cordata, B.S. Bart., Amirante, 20 and 30 fms. Coetivy reef. Seychelles, 34 fms. 
Saya de Malha, 26 and 29 fms. Salomon reef. 
Geogr. Distr. Atlantic. Indian Ocean. Pacific. 
34. H. gracilis, Harvey, ex J. Ag. Till Alg. Syst. vii. (1887) p. 82; E.S. Bart. 7. ¢. 
p. 22, t. 3. 
f. typica, E. 8. Bart., Amirante, below 20 fms. and below 25 fms. Saya de Malha, 
25 and 29 fms. 
Geogr. Distr. Atlantic. Indian Ocean. Pacific. 
30. H. incrassata, Lamour. l.c. p. 186; E. 8S. Bart. J. ¢. p. 25, t. 4. 
f. typica, EK. 8. Bart. (with rather small joints). Chagos Archipelago: Coin, Peros, 
reef. Egmont. 
f. monilis, HK. 8. Bart., Amirante, 25 fms. Coetivy reef. Saya de Malha, 25 fms. 
(between ¢ypica and monilis). Cargados Carajos, 47 fms. 
f. ovata, J. Ag., Seychelles: Praslin reef. Amirante, 44-20 fms. Saya de Malha, 
26 fms. Cargados Carajos, 30 fms. Chagos Archipelago: Salomon reef; Egmont reef 
and lagoon shoal. 
Geogr. Distr. Atlantic, Indian Ocean. Pacific. 
pase) 53* 
