the last segment; each side of this band the mottlings are 6 A second British species was named Gebia deltäura by Leach, on the ground that the interior lamella of the tailfan is truncate and formed like the Greek Delta.' No doubt he was alluding to the inner branch of the uropods. This is an obscure feature on which to base the specific name, and Bell has been not unnaturally misled into supposing that Leach was referring to the telson, which, however, is not at all deltoid in form, and which Leach himself expressly describes as 'quadrate' and nearly quadrate.' According to Leach this species lives with G. stellata,' and Bell suggests that it is probably identical with it. The Mediterranean Gebios littoralis," Risso, is a nearly allied species, which ranges to the coast of Norway, and may therefore be expected to occur in intermediate waters. The name Gebia no doubt signifies 'life in the ground,' and Upogebia subterranean life,' in allusion to the burrowing habits which make specimens of the genus rare. The young ones, however, may be taken pretty plentifully at the surface, and Sars has in consequence been able to describe the first larval stage or Zoea-form, the second or transition from Zoea to Mysis stage, the third or Mysis-form, the last larval stage, and the first post-larval stage of adolescence (see Plate IX.) From these descriptions it will be seen, he observes, that Gebia in some respects is very distinct from Nephrops and Calocaris, two of the genuine Macrura which he had previously been examining, as well as from all the Carides, while in several points of development it approaches the Anomura. In the Carides as in Calocaris the rule appears to be that the first larval stage or Zoea form is characterised by the presence of three pairs of welldeveloped swimming appendages, representing the exopods on the three pairs of maxillipeds, while the endopod of the last pair of maxillipeds is fully developed, distinctly articulated 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 undeveloped 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 Mysisstage is passed through, in which not merely the three pairs of maxillipeds, but also the first three pairs of trunklimbs 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 larvæ 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.-Axiida. 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 branchiæ are filamentous, cylindrical, and compressed. The family contains three genera, one of them British. Axius, Leach, 1815, has for type species Axius stirynchus, Leach, first found at Sidmouth. Norman says that this species has 'the telson quadrangular, the hands smooth, the fingers channelled, the particular articulation of cephalothorax 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 the appearance of a dried specimen. Spence Bate declares that ‘Axius has been taken only on the southern coast of England,' but Bell and Marion have reported it from the Mediterranean and Milne-Edwards from the coasts of France. The name of the species may be guessed to signify with a stiff rostrum.' The same feature belongs to a second species, Axius glyptocĕrus, von Martens, found in Australian waters. The second antennæ in this genus have a movable spine or scale representing the exopod on the second joint. Paraxius, Spence Bate, 1888, was founded for a species taken off Celebes Island, in which the second antennæ have no 'scaphocerite,' that is, no scale, spine, or other representative of the exopod on the second joint, and no 'stylocerite.' Eiconaxius, Spence Bate, 1888, has three species, all taken from depths of some hundreds of fathoms in the Pacific. Here the second antennæ have the peduncle furnished with a scaphocerite and stylocerite.' 'This genus,' the author says, differs from Pararius in having both scaphocerite and stylocerite, which are absent in that genus; this character also separates it from Axius, which has a small scaphocerite only. The stylocerite, which is present in this genus, is wanting in Axius, as it is in all the Macrura, except Eiconaxius and Cheiroplatea. Its presence is a feature most prevalent in the Anomurous Crustacea.' In the description of the type species, Eiconaxius acutifrons, Spence Bate says of the second pair of antennæ, its third joint is externally produced to a long sharp tooth or stylocerite.' Yet in his glossary 'stylocerite' is defined as 'style or large spine on outer margin of the first joint of the first pair of antennæ,' and in the Introduction to his Report on the Challenger Macrura, he attributes a stylocerite to the first antennæ in species of Penaeus, &c., but states that it does not exist in the Trichobranchiata. Under all the circumstances it seems as if it would be just as well to call a spine a spine instead of a stylocerite. The single specimen of Eiconaxius parvus, half an inch long, taken from a depth of 520 fathoms, had |