MONTAGU'S CALLIANASSA 183 Family 2.-Callianasside. The carapace is laterally compressed, with rostrum minute or absent. The eyes and antennæ are as in the preceding family. The first pair of trunk-limbs are unequal, perfectly or imperfectly chelate, the third and fourth pairs simple, the others variable. The uropods and telson are usually broad, without sutures. The branchiæ are filamentous, with the filaments sometimes compressed. Six or seven genera are assigned to this family, of which two are British. Callianassa, Leach, 1814, was instituted to receive a species which Colonel Montagu described in 1805 (and published in 1808) under the name Cancer Astacus subterraneus. He found it at the depth of nearly two feet beneath the surface, while digging into a sandbank in the estuary of Kingsbridge or Salcombe in South Devon. Though it was by no means plentiful, he ascertained that the larger arm was not constant to one side, and that the extreme disproportion sometimes exhibited by it was not invariable. The crustaceous covering of the body he describes as 'very thin and not far remote from membranaceous.' The exceedingly narrow attachment between the first four joints of the larger cheliped and the following three which form its monstrous termination give to this species a very peculiar appearance. The second pair of feet are minutely chelate. The second pair of pleopods are slender and filamentous, while the following three pairs are broad and foliaceous. A. Milne-Edwards in 1870 distinguishes seventeen recent species. Czerniavsky in 1884 points out that the Mediterranean Callianassa laticauda, Otto, should be added to the list. Callianassa Stimpsoni, Smith, is a species found on the east coast of the United States. This and other deepburrowing crustaceans are more often obtained from the stomachs of fishes than by intentional methods of capture. Cheramus, Spence Bate, 1888, was instituted chiefly on account of the contradictions in different writers in regard to the third maxillipeds of Callianassa, some calling them pediform, others operculiform. In Cheramus they are distinguished as pediform, but it seems rash to establish a new genus on the very character which some authors ascribe to the old one, especially as Callianassa is not unrepresented in England, France, and the Mediterranean, and specimens might have been examined to clear up the disputed point. In the British Museum Leach's type-specimens of Callianassa subterranea, from Kingsbridge in South Devon (Salcombe at the mouth of the Kingsbridge estuary being probably intended), have third maxillipeds that might well be described as pediform. But other specimens at the same museum, which have been labelled as belonging to the same species, were shown me by Mr. Pocock, and in these, which came from Jersey, the third and fourth joints of the maxillipeds in question are greatly expanded, quite deserving the name operculiform. But these specimens also have a more quadrate telson than those from Devonshire, and are doubtless quite distinct. Since, however, in the type of Callianassa the maxillipeds are pediform, the chief reason for the institution of Cheramus is cut away. Its name signifies a gap,' but it has not succeeded in filling one. Callianidea, Milne-Edwards, 1837, closely resembles Callianassa, but with some differences in the branchial arrangements, and, besides having the second pleopods. like the following three pairs, in all these pleopods 'the margins, instead of being fringed with small hairs or cilia, have these modified into soft and flexible articulated membranous filaments.' Milne-Edwards supposed that these were true branchial appendages, and that a link was thus established between this family and the Squillidæ in the sub-order Stomatopoda. With his own genus he coupled Guérin's Isea. But Mr. Spence Bate regards it as probable that Guérin's genus was founded on a damaged specimen of Callianidea, and with some reason thinks that the fringed pleopods of that genus cannot be regarded as branchial for purposes of classification. UPOGEBIA BROUGHT TO LIGHT 185 Upogebia, Leach, 1814, was founded to receive another species discovered by the industrious Montagu, and described by him in 1805 (1808) as Cancer Astacus stellatus. The colour, he says, is 'yellowish-white, covered with minute stellated orange spots, as it appears under a lens, which give a predominance to the last.' In this genus the first pair of legs are subequal and subchelate, the other pairs being simple; the second pair of pleopods is like the three following pairs, with the margins strongly ciliated; the components of the swimming fan are broadended. It seems to have escaped the notice of writers subsequent to Leach that the earliest name of this genus was Upogebia, which must therefore be retained in preference to Leach's own alteration of it into Gebia, or Risso's Gebios. Bell refers to the Edin. Encycl., xi. p. 400,' as an authority for Gebia stellata, printing xi. by mistake for vii., and probably guessing at Gebia by mistake for the actual Upogebia. The type species was taken along with the type of Callianassa. On the nearly allied American species described by Say, Verrill and Smith make the following observations :—'The Gebia affinis is a crustacean somewhat resembling a young lobster three or four inches in length. It lives on muddy shores and digs deep burrows near lowwater mark, in the tenacious mud or clay, especially where there are decaying sea-weeds buried beneath the surface. The burrows are roundish, half an inch to an inch in diameter, very smooth within, and go down obliquely for the distance of one or two feet, and then run off laterally or downward, in almost every direction, to the depth of two or three feet, and are usually quite crooked and winding. We have found them most abundant on the shore of Great Egg Harbour, New Jersey, near Beesley's Point, but they also occur at New Haven and Wood's Hole, &c. This species is quite active; it swims rapidly and jumps back energetically. It is eagerly devoured by such fishes as are able to capture it. When living the colors are quite elegant. Along the back there is a broad band of mottled, reddish brown, which is contracted on the next to the last segment; each side of this band the mottlings are fewer, and the surface somewhat hairy. The last segment and the appendages of the preceding one are thickly specked with reddish brown; their edges are fringed with grey hairs.' Leach's statement that Upogebia stellata makes winding horizontal passages in the mud, 'often of a hundred feet or more in length,' appears still to await confirmation. 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 brauch 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 Gelia 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 |