LARVAL LINKS 187 
on the three pairs of maxillipeds, while the endopod of the 
last pair of maxillipeds is fully developed, distinctly articu- 
lated and setiferous. On the other hand in Gebia, or, to 
give it its right name, in Upogebia, as in the Brachyura and 
Anomura, this last pair of maxillipeds is entirely unde- 
veloped in the first larval stage, the exopod or swimming 
branch being developed later on, but the endopod remaining 
undeveloped during the whole larval life. But again from 
both Brachyura and Anomura the larva of Upogebia is 
distinguished, because, just as in the Carides, a real Mysis- 
stage is passed through, in which not merely the three 
pairs of maxillipeds, but also the first three pairs of trunk- 
limbs are furnished with swimming-branches. As to the 
intimate structure of the maxillipeds and mouth-organs 
generally, Sars remarks that the larva of Upogebia shows 
a very striking likeness to the larve of certain Anomura, 
for example, Galathea. 
The Jaxea nocturna, Nardo, 1847, which Heller in 
1856 called Calliaxis adriatica, may belong to this family, 
but the rostrum is well marked. 
Family 3.—Aziide. 
The carapace is produced to a horizontally flattened 
point or rostrum. The first pair of trunk-legs are chelate 
and subequal; the second pair are small, chelate, equal ; 
the last three pairs are simple. The first segment of the 
pleon is very short. The outer branch of the uropods is 
not longer than the inner. ‘The branchize are filamentous, 
cylindrical, and compressed. The family contains three 
genera, one of them British. 
Awius, Leach, 1815, has for type species Awvius stiryn- 
chus, Leach, first foundat Sidmouth. Norman says that 
this species has ‘ the telson quadrangular, the hands smooth, 
the fingers channelled, the particular articulation of cepha- 
lothorax and abdomen described by Mr. Couch, and the 
transverso-lateral tufts of hair on the abdominal segments.’ 
He supposes that Leach and Bell, in attributing an 
elongate-triangular form to the telson, were misled by 
