Photis brevicaudata Stebbing. (Fig. 3, A to E.)

Photis brevicaudata Stebbing, 1888, p. 1068, pl. 108; 1906, p. 606; 1910, p. 648.

Several specimens that certainly belong to this species were obtained near the Gannet Islands, off the west coast of Auckland, in January, 1915, at a depth of about 50 metres. The species were originally described from specimens obtained by the “Challenger” Expedition off Melbourne, Australia, at a depth of 60 metres, but only the female was then taken.

My specimens agree well with Stebbing's description and figures of the female; in the first gnathopod the palm is slightly concave, as shown in his detail figure. The male specimens differ from the female in the size and shape of the second gnathopod, but particularly in the great elongation of the fourth peraeopod. The second gnathopod of the male has the shape in general like that of the female described by Stebbing, but the propod is larger, the palm much more excavate, and the angle defining it much more marked. The fourth peraeopod in the older males is very greatly enlarged, being much larger and broader than the fifth, as will be seen by comparing figs. 3D and 3E. The basal joint is broad, narrowing distally, the meral joint is greatly elongated, being longer than the carpus and propod together; the details as to the proportions of the joints can be best learnt from fig. 3D. The other appendages agree well with the description given by Stebbing.

In the male specimen from which fig. 3B of the second gnathopod was taken the first gnathopods were unsymmetrical. One, shown in fig. 3A, is practically the same as that of the female. The one from the other side (fig. 3c) has the propod similar to that of the second gnathopod, though rather smaller, but the carpus is much longer than in the second gnathopod, and therefore more like that of a normal first gnathopod.

The great enlargement of the fourth propod in this species recalls the somewhat similar development of the same appendage in Eurystheus crassipes (Haswell).

Stebbing describes the telson as “very short, much broader than long, apex rounded,” and figures it without setules. In the specimen I have examined the apex is less rounded, and bears setules on either side as in P. macrocarpa Stebbing and other species of the genus.