the trunk, a mistake which Professor Smith has now corrected. Remipes testudinarius, Latreille, has been recorded by this and various other names from many parts of the Indo-Pacific region. Its true name would seem to be Remipes adactylus (Fabricius). Remipes scutellatus (Fabricius) is found in the Atlantic.

Mastigochirus, Miers, 1877, meaning 'with a whip-like hand,' was previously called Mastigõpus by Stimpson in 1858, but the name being pre-occupied had to be changed. Its chief distinction from Remipes rests on the form of the long and slender first pair of legs, which have the terminal joint subdivided. The type specimen of Mastigochirus quadrilobatus, Miers, came from the Philippine Islands. A comparison of this with others subsequently obtained by the Alert in the Prince of Wales' Channel showed Mr. Miers that the number of joints in the terminal flagelliform portion of the anterior limbs (which are imperfectly seen on account of the hairs with which they are thickly clothed) was understated in the original description; instead of being ten or twelve, they are usually twice as numerous.'

Family 2.-Albuneida.

The third maxillipeds are subpediform, with the fourth joint not greatly dilated; there is a small exopod. The first pair of legs are flattened and chelate. The telson is ovoid.

Albunea, Fabricius, 1798, has for its type species the little Albunea symnista (Linn.), from eastern waters. The carapace is strongly grooved behind for the reception of the small first segment of the pleon. In Milne-Edwards' 'Histoire Naturelle des Crustacés,' vol. 2, p. 202, the distinguishing characters of Remipes and Albunea are transposed, but the error is subsequently corrected.

Legion 2.--Lithodinea.

The carapace is broadly ovate, uneven, with the regions well defined and a prominent rostrum. The first antennæ have cylindrical peduncles of moderate size and short

12

flagella. The second antennæ have an acicle on the second joint. The third maxillipeds are subpediform, with the third and fourth joints elongate. The first legs of the trunk are chelipeds; the three following pairs are well developed, more or less cylindrical, and the last pair are slender, chelate, folded in the branchial chambers. The sternal plastron is wide. The pleon is bent under the trunk, having the first segment small and dorsally fused with the second; it has appendages only in the female, these being a rudimentary pair on the first segment, and, as a rule, a single one-branched appendage on the left side of each of the four following segments.

The single family Lithodidæ has the characters of the legion. The members of it are found in the cold and temperate shallow waters of both hemispheres, but deep-sea dredgings, especially those of the Talisman, have shown that at great depths, even below a thousand fathoms, species occur in the tropics. Thus, it has been pointed out, the Arctic and Antarctic zones are connected by a submarine tunnel of cold water. The genera are not very numerous. One is found in the waters of Great Britain. Lithōdes, Latreille, 1806, is now represented by several fine species from distant parts of the world. Lithodes maia (Linn.) has long been known. It is the devil-crab of the Norwegian fishermen, according to Herbst. Bell calls it the Northern Stone Crab, and is surprised that what he calls its slight resemblance to Maia squinado should have caused it to be at times confused with that species. The superficial resemblance, however, is not inconsiderable, when the dorsal view alone is regarded. The ventral view permits of no confusion or mistake, for in Lithodes the pleon has in the third, fourth, and fifth segments paired calcified plates, the median portion being membranous with scattered calcareous particles. In the female the plates are greatly developed on the left side to the disparagement of those on the right, producing a want of symmetry akin to that which is found in the Paguridæ. The rostrum in Lithodes is spinulose, like almost all the other external parts of the animal. Lithodes histrix, de

Haan, portrayed in the adjoining Plate, is called by the Japanese Aka-oni-gani, which according to de Haan means the red crab of the devil. Lithodes Agassizii, Smith, has been taken in the Atlantic from depths of a thousand and twelve hundred and fifty fathoms. Lithodes Murrayi, Henderson, was obtained in the Southern Ocean from three hundred and ten fathoms depth.

Cryptolithodes, Brandt, 1849, with its species Cryptolithodes typicus, Brandt, from California, is especially distinguished by the great development of the carapace, which completely hides the legs, antennæ, and pleon, and these when viewed from below appear to be placed in the bottom of a cup-like cavity. According to Stimpson, this development of the carapace is unequalled in any even of the higher decapods, not excepting Cryptopodia and Ethra, and this is the only instance in which the carapace conceals all the feet.

Echidnocerus, White, 1848, contains one or two massive species from the West Coast of America, the carapace in Echidnocerus setimănus (Gibbons) sometimes measuring ten inches in length and as many in width, and by a weight of over seven pounds exceeding that of the carapace even of the giant Macrocheira of Japan.

FIG. 13.-Lomis dentata [de Haan].

Lomis, Milne-Edwards, 1837, has a very small rostrum, consisting of a single tooth. The little Lomis dentata is described by de Haan from Japan. Its carapace about half an inch in diameter forms a strong contrast to the preceding species.

Paralomis, Stimpson, 1858, has a rostrum which is usually trispinose, and in this genus the third, fourth, and fifth segments of the pleon in the female have the lateral plates subequal, and the median portion occupied by a series of large calcareous plates. instead of particles.

Hapalogaster, Brandt, 1851, has the appendages of the second pleon-segment in the female biramous instead of one-branched as in the other Lithodidæ. Its second antennæ are much longer than the carapace, as in Porcel