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 UpogeUa shows 

 a very striking likeness to the larvas of certain Anomura, 

 for example, Galathea. 



The Jaxea nocturna, Nardo, 1847, which Heller in 

 1856 called Calliaxis achiatica, may belong to this family, 

 but the rostrum is well marked. 



Family 3. Axiidce. 



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 branchia3 are filamentous, 

 cylindrical, and compressed. The family contains three 

 genera, one of them British. 



Axius, Leach, 1815, has for type species Axius stiryn- 

 c/ms, Leach, first found at 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 



