100 
Proceedings of the Eoyal Society 
Octopus tonganus, Hoyle. 
Octopus tonganus , Hoyle, Ann. and Mag. Nat. Hist., ser. 5, vol. xv. 
p. 225, 1885. 
The Body is rounded, depressed, and broader than long, with a 
marked but shallow median groove on the ventral surface. Mantle- 
opening extends about one-third round the circumference of the 
body, terminating nearer to the funnel than to the eye. The siphon 
is short and conical, and extends rather more than halfway to the 
umbrella margin. 
The Head is small and the eyes prominent. 
The Arms are unequal, the order being 3, 2, 4, 1 ; on an average 
they are nearly ten times as long as the body, and taper gradually 
to very fine points. The umbrella is very small, and slightly 
narrower dorsally than laterally. The suckers are for the most part 
small and closely packed ; the first four are arranged in a single 
row ; in the male there are four large ones on each lateral arm 
opposite the margin of the umbrella, beyond which they gradually 
diminish. The heetoeotylus is very minute. 
The Surface is in general smooth ; the back bears a few small 
papillse, but owing to the compression of the specimens it is impos- 
sible to make out their exact number. There are three minute 
cirri over each eye. 
The Colour is on the whole grey, paler below ; this is due to dark 
specks sprinkled more or less closely over a cream-coloured ground. 
One specimen has a purplish patch at either side of the mantle- 
opening. 
Habitat. — The reefs, Tongatabu. 3 mutilated specimens, 1 Si 
2 ?. 
i Octopus vitiensis, Hoyle. 
Octopus vitiensis, Hoyle, Ann. and Mag. Nat. Hist., ser 5, vol. xv. p. 
226, 1885. 
The Body is nearly oblong, but becomes somewhat narrower 
posteriorly. The mantle-opening extends nearly one-third round 
the body, and terminates some distance below and behind the eye. 
The siphon is long and acutely pointed, and extends about half- 
way to the umbrella-margin. 
The Head is broader than the body, with large laterally prominent 
eyes. 
