476 ETHEL S. BARTON ON THE MARINE ALGE 
4, Hatimepa Opuntia, Lamz., forma TyPica, Bart. 
Minikoi, Laccadive Islands; from shoal in centre of lagoon. 
Rare everywhere on the Minikoi reef; but small masses may be 
found by searching under stones or in protected situations of the 
inner part of the reef, near the beach or boulder zone. In 
lagoon, not found in currents, but very luxuriant in moderately 
still water where it can find any stones to fix itselfupon. Addu 
Atoll, Maldive Islands; at 25 fathoms; hard bottom outside 
atoll. Suvadiva Atoll; from fine mud at 45 fathoms. 
Forma rritosa, Bart. 
Suvadiva Atoll, Maldive Islands. From muddy sand at 
43 fathoms. 
Geogr. Distr. Atlantic, Indian Ocean, Pacific. Tropical. 
5. H. rrorassata, Lamex., form between f. typica and f. La- 
MOouUroUxit. 
Addu Atoll, Maldive Islands. 25 fathoms; hard bottom 
outside atoll. 
Geogr. Distr. Atlantic, Indian Ocean, Pacific. Tropical. 
6. VALONIA CONFERVOIDES, Harv. 
Minikoi, Laccadive Islands. Forming with Gracilaria crassa 
a feltwork found very commonly towards the edge of the reef, 
almost up to the inner ends of the fissures, and abundant in the 
strong outrushing currents and on the buttresses, a few yards 
in from their edges, 
Geogr. Distr. Warm Atlantic, Indian Ocean, Pacific, Aus- 
tralia. 
PHMOPHYCESR. 
7. SARGASSUM DUPLICATUM, Agh. 
Minikoi, Laccadive Islands. With Turbinaria ornata and 
Gelidium rigidum. Very common all over the reef right round 
the atoll. Not found in lagoon. Occurs only in parts where 
there is no sand; and never uncovered at low tide. Not found 
near the outer edge of the reef, the whole bottom being covered 
with incrusting Lithothamnion ; nor in the fissures, apparently 
not being able to live in the very strong currents formed by the 
outrushing waters after each breaker. 
Geogr. Distr. Indian Ocean, South Pacific. 
