Octopus tonganus, Gunther & Dallas & Carruthers & Francis, 1885

Gunther, Albert C. L. G., Dallas, William S., Carruthers, William & Francis, William, 1885, The Annals and Magazine of Natural History, Including Zoology, Botany, and Geology, Reptiles and Batrachians from Brazil, LONGMANS, GREEN, AND CO.; SIMPKIN, MARSHALL, AND CO.; KENT AND CO.,; WHITT AKER AND CO.: BAILLIERE, PARIS: MACLACHLAN AND STEWART, EDINBURGH: HODGES, FOSTER, AND CO., DUBLIN: AND ASHER, BERLIN: TAYLOR AND FRANCIS, pp. 1-96 : 225-226

Octopus tonganus , n. sp.

The Body is rounded, depressed, and broader than long, with a marked but shallow median groove on the ventral surface. The 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 hectocotylus is very minute.

The Surface is in general smooth; the back bears a few small papillae, but owing to the compression of the, specimens it is impossible 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 creamcoloured ground. One specimen has a purplish patch at either side of the mantle-opening.

Hab. The Reefs, Tongatabu. Three mutilated specimens, 1♂ 2♀.