A MEDLEY OF ANIMALS

403

brought together, and, as it were, jumbled up into a sort of compound animal, so that when the Pagurid devours a shrimp, its gastronomic exertions are supplying food through the remnants of a shapeless Cirripede to a degraded Isopod. This remarkable arrangement on the body of a hermit-crab, itself occupying the shell of a departed mollusc, must be regarded as the result of special creation by those who still uphold the venerable doctrine of the fixity of species. What a gasp an intelligent mind must give at swallowing such an explanation!

Cryptoniscus paguri, Fraisse, 1878, was found on Peltogaster Rodriguezii, Fraisse, on Clibanarius misanthropus, Risso, at Mahon in Minorca. It is described as flat and worm-like, much resembling the preceding species.

Cryptoniscus larvæformis, Giard, 1874, on Sacculina

carcini.

Danalia, Giard, 1887, was substituted for part of Zeuxo, Kossmann, 1872, preoccupied.

Danalia curvata (Fraisse), 1878, on Sacculina neglecta, Fraisse, from the Bay of Naples, is said to be round and rolled together, very like the Cabirops lernæodiscoides of Kossmann. Dr. Fraisse says that it is either a simple parasite on the Sacculina, or placed beside it on the crab Inachus scorpio, Fabricius, but that in any case it has to draw its nourishment from the roots of the Sacculina.

Danalia Lobiancoi, Giard and Bonnier, 1890, on Portunascus corrugatus, Giard.

Danalia Dohrni, Giard, 1887, on Grapsisaccus Benedeni, Kossmann. The Zeuxo longicollis of Kossmann, 1880, was found on the pleon of Chlorodius (Leptodius) exaratus, Milne-Edwards, in company with but remote from a Sacculina.

Liriopsis, Max Schultze, 1859, was substituted for Liriope, Rathke, 1843, preoccupied.

Liriopsis pyymaa (Rathke), 1843, on Peltogaster paguri, Rathke. The first antennæ have a very thick bundle of hairs attached to the outer side of the basal joint in the male.

Liriopsis monophthalma (Fraisse), 1878, on Peltogaster

curvatus, Kossmann, is said to have a cylindrical form, and to be nearly related to the preceding species.

Eumetor, Kossmann, 1872. The male allied to Liriope (Rathke), but without antennæ; the female much larger, its segmentation continuing in the mature state.' (Zool. Record,' 1873).

Eumetor liriopides, Kossmann, 1872, in the mantlecavity of Sacculina pisiformis, from the Philippines. Dr. Fraisse, discussing specimens which he supposes to belong to this genus, from the mantle of Sacculina Benedenii, says that no brood-cavity is present, the Isopod being content to use the mantle of the Sacculina for that purpose. He also says that the male of Kossmann's species has no olfactory setæ on the inner antennæ.'

Cryptothir, Dana, 1852, on non-parasitic Cirripedes. Cryptothir minutum, Dana, in the corallidomous barnacle Creusia, at the Fiji Islands.

Cryptothir balani (Bate), 1861, on Balanus balanoides. The larval form, as taken with the tow-net in the Clyde, has eight teeth on the basal joint of the first antennæ; the second antennæ nine-jointed; the mouth-organs forming a triangular mass, with the apex pointing backwards; the sides of the peræon, and in a less degree those of the pleon, digitate; the first two pairs of trunk-limbs not degraded, strongly subchelate, the next three pairs slightly so, the last two pairs simple, with the two terminal joints elongate; the five pairs of pleopods and the uropods two-branched, the branches tipped with setæ. According to Bate and Westwood, the adult sedentary female is a lobate sackformed mass without any appendages.

The genus Hemioniscus, Buchholz, 1866, is said to be a synonym of Cryptothir. But according to Buchholz the adult female of his Hemioniscus balani retains the front part of the larval form. This, however, may not be permanently the case. Beddard mentions a Bopyrid in the larval stage attached to Serolis cornuta, Studer, on the dorsal surface of some of the anterior segments, and 'apparently belonging to the genus Hemioniscus,' but this parasite has not been described.

POCKETED PARASITES

405

Leponiscus, Giard, has the single species Leponiscus pollicipedis, parasitic, as the name indicates, on a pedunculate Cirripede.

The animals are parasitic (to appearance) within the bodies of Brachyura, entering through the branchial into the visceral cavity. In the females the body is extremely unsymmetrical, with traces of segmentation when young; the head is swollen into a double sphere, the antennæ are metamorphosed into lips; the labrum, hypostome and mandibles forming the oral apparatus. The maxillipeds are lamellar, the feet rudimentary, the marsupium formed of five pairs of plates, with the first pair situated between the rest; the ovaries opening at the base of the fifth pair of feet, and by their prolongations determining the shape of the peræon; the pleon has six segments, furnished with lamellar or sabre-shaped pleopods. In the minute male there are two rudimentary eyes, the antennæ are evanescent, the maxillipeds are rudimentary, the seventh segment of the peræon is without appendages; the six segments of the pleon are without pleopods. The embryo has two eyes, sometimes a nauplian eye, the second antennæ elongate, six pairs of feet, five pairs of pleopods and even a pair of uropods. In the 'Cryptoniscian stage' there are seven pairs of feet. MM. Giard and Bonnier give a provisional genealogical tree of the Entoniscidæ in connection with their hosts.

These are in reality ectoparasites, though with an appearance of being endoparasites. The sheath or enveloping membrane moulded on every detail of their bodies is an invagination of the hypodermis of the crab in which the Entoniscid lives.

Entoniscus, Fritz Müller, 1862. Parasitic on Porcellanidæ. The female has the marsupium open when adult, with deeply cut edges to the component plates, and an elongate pleon with five pairs of sabre-shaped pleopods. The male is comparatively large, with the first antennæ elongated, six pairs of trunk-feet reduced to pedicellate tubercles, and the last segment of the pleon not slit.

Entoniscus porcellanæ, Müller, 1862, on Porcellana sp. Entoniscus Mülleri, Giard and Bonnier, 1886, on Porcellana longicornis (Linn.).

Entoniscus brasiliensis, Müller, 1871, on Porcellana sp. Entoniscus Creplinii, Giard and Bonnier, 1887, on Porcellana (Polyonyx), Creplinii, Müller. Fritz Müller found a couple of the Porcellana in almost every tube of the Chaptopteri at Desterro. Only three times did he find the Porcellana solitary, once a female, twice a male. Only on these three specimens did he find an Entoniscus. The parasite makes the animal sterile, and it is inferred that the infested crabs either could not find or retain partners. Possibly they did not make the attempt to do either one or the other.

Entione, Kossmann, 1881. The male has the last segment of the pleon terminally bifid. This genus since its institution has been much subdivided, and the original name limited to Entoniscidæ parasitic on Oxyrrhyncha.

Entione achai, Fritz Müller, on Achæus sp.

Grapsion, Giard and Bonnier, 1886. Parasitic on Grapsida. The female has the marsupium closed when adult, the ascendant lamella of the first pair of marsupial plates narrow all along; there are two medio-ventral and two latero-dorsal ovarian bosses and four dorsal tubercles; the pleopods lamellar, little recurved. The male has the sixth segment of the pleon ending in two recurved hooks.

THE ENTONISCIDE

407

The embryo has a nauplian eye, and swims with the sixth pair of trunk-feet extended.

Grapsion Cavolinii, Giard (1878), on Pachygrapsus marmoratus, Fabricius. This species is named after Cavolini, who in 1792 described an Entoniscid from Granchio depresso,' which is supposed to be the same as Pachygrapsus

marmoratus.

Cancrion, Giard and Bonnier, 1886. Parasitic on Cancridæ. The female has the marsupium closed when adult, and has four dorsal ovarian bosses. The sheath in which the animal is enclosed is always covered with thickenings of yellow chitin. The male has the pleon clearly distinct from the peræon, elongate, without ventral prominences or terminal hooks, the bilobed apex of the sixth segment being minutely squamose. The embryo has the sixth trunk-feet elongate and carries them extended laterally.

Cancrion cancrorum (Fritz Müller, 1864), on several Brazilian species of Xantho, implying ex hypothesi several species of parasite under one name. Fritz Müller states that the heart in the male is situated in the third segment of the pleon.

Cancrion miser, Giard and Bonnier, 1886, on Pilumnus hirtellus (Linn.) Six specimens were found. The crabs examined were more than 1,800.

Cancrion floridus, Giard and Bonnier, 1886, on Xantho incisus, Leach, commonly called Xantho floridus (Montagu). Three specimens were found to about 900 crabs examined.

Portunion, Giard and Bonnier, 1886. Parasitic on Portunidae. The female has the marsupium closed when adult, the ascendant lamella of the first pair of plates regularly widened from the base, much recurved, the upper edge not cut; there are two medio-ventral and two latero-dorsal ovarian bosses. The male has medio-ventral hooks on the pleon, and the sixth segment apically furnished with a pair of hooks. The embryo is without a nauplian eye, and swims with the sixth trunk-feet carried under the pleon.

Portunion manadis, Giard, 1886, on Carcinus mœnas