244 Transactions.—Zoology. 
The young, taken from the incubatory pouch of the female, differ some- 
what from the adult. The back is smooth and rounded, whereas in the 
adult it is sharply keeled, and the segments of the pereion are produced 
posteriorly into teeth. The pereion is very broad and expanded. Antenne 
subequal; superior stout and conical, three-jointed, terminal joint with a 
few short sete at the extremity and two longer ones projecting at right 
angles from near the middle of the inferior margin ; inferior pair somewhat 
more slender, and with very minute sete. Some of the appendages also 
. are either wanting or are not fully developed, probably the first or second 
pair of gnathopoda. Pleopoda normally developed. 
These minute creatures approach in form and general appearance to 
Hyperia cyanea much more than Themisto. Every adult female had several 
of them in the ineubatory pouch under the pereion. 
Frequently washed up on Ocean Beach, Dunedin. 
Fam. ITI. Platyscelids. 
Cephalon round. Eyes large. Antenne attached to the inferior surface. 
Epistoma proboscidiform; oral appendages rudimentary. Gnathopoda 
complexly subehelate. First two pairs of pereiopoda simple; two succeed- 
ing pairs having the basa largely dilated; fifth pair imperfectly developed. 
Posterior pleopoda foliaceous. 
Genus Platyscelus, Spence Bate, 
Brit. Mus. Cat. Amphip. Crust., p. 329. 
Cephalon transversely ovate. Pereion distended ; first segment narrower 
than the cephalon. Pleon much narrower than the pereion, having the 
fourth and fifth segments coalescing, the fifth and sixth pairs of pleopoda 
being attached to the posterior margin; sixth segment and telson fused 
together, the posterior pair of pleopoda being attached to the under surface 
near the middle of the segment. Superior antenne short, consisting of a 
peduncle and a flagellum. Inferior antenne not longer than the cephalon, 
consisting of four joints, concealed beneath the cephalon, not folded. 
Mandibles without an appendage. Third pair of pereiopoda having the 
basos largely dilated, and the remaining joints shorter than the basos ; 
fourth pair having the basos twice as large as the third, the remaining 
joints not half so long as the basos; fifth pair membranous, a small 
tubercle representing the PORE joints. Three posterior pairs of 
pleopoda biramous, foliaceous, Telson obtusely triangular. 
20. Platyscelus intermedius, nov. sp. Fig. D.4. 
Cephalon rounded in front, First two segments of pereion very narrow; 
succeeding broader, subequal. Eyes very large, oceupying nearly the whole 
~ eephalon, with a large triangular red pigment spot on the outside of each. 
Epistoma triangular. Antenne placed quite underneath the epistome. 
