Lib, Con +0.04. mus.

8-24-37

34049

ANNALS

OF THE

SOUTH AFRICAN MUSEUM.

(VOL. VI.)

I.-South African Crustacea (Part IV.*).-By the Rev. THOMAS
R. R. STEBBING, M.A., F.R.S., F.L.S., F.Z.S.

THE scope of the present contribution is enlarged by including
several species of Amphipoda—a group of which very few members
have been hitherto recorded from South African waters. Seven
of the species now noticed claim to be new, one of them even
demanding the institution of a new genus. But, as in many other
groups of Crustacea, so in this, the novelty of the characters is less
striking than the close general relationship between the forms found
here and others earlier known and described from many very remote
localities. In regard to the new species of the curious genus.
Trischizostoma, it is desirable to call attention to the important
contemporary discussion of that genus by Mrs. E. W. Sexton,
working at the Plymouth Laboratory. As an example of widely
ranging genera the coincidence may be noted that the description
of the remarkable prawn, Leontocaris paulsoni, from the Cape, had
only been a few months published in Part III. of this series when
Mr. Stanley W. Kemp was able to announce a second species of
this highly specialised genus from the west coast of Ireland, taken
at a depth of 500 fathoms in lat. 53° N., outside the "Porcupine
Bank."

Besides the numerous specimens due to Dr. Gilchrist's "Marine Investigations," the present report deals with a large collection submitted to me from the Durban Museum. When sending this valuable * The other three Parts have been published in "Marine Investigations in South Africa."

consignment, Mr. J. F. Quekett wrote, saying, "The spirit specimens are from Durban, except two from Algoa Bay, which are so marked. The dried specimens are mostly from Agulhas Bank, Cape Colony, but the Mantis shrimps are from here." There is, therefore, some vagueness in regard to the place of origin of the dried specimens. It has not appeared necessary to mention them all on the present occasion. Also some Penæidea and Caridea have been left over for future consideration. The collection furnishes an interesting new species of the genus Mamaia; this again showing close relationship to European and Japanese kindred. When its description and illustration were already in the hands of the printer, a second and in some respects finer specimen was sent me by Mr. F. W. FitzSimons, Director of the Port Elizabeth Museum. This and a fresh example of another interesting species from the same source and locality will be further noticed in their turn.

Along with two new species of Isopoda the report discusses in various groups some established species on which it appeared that fresh light could be thrown or desired. In the Palæmonidæ the new generic name Macroterocheir is proposed in place of what seems to be the illegitimate use of the term Macrobrachium. The name Squilla oratoria, de Haan, is upheld as prior to Berthold's S. affinis. Lastly, it should be noted that some references are given to William Stimpson's report on the Brachyura and Anomura collected by the North Pacific Exploring Expedition, 1853-1856. Stimpson died in 1872, pathetically believing that his manuscript and drawings for that work had been destroyed in the great fire at Chicago during the preceding year. His report, however, was subsequently found to be safe at the Navy Department, and was transferred to the Smithsonian Institution, which has now earned the thanks of the scientific world by publishing it under the able editorship of Miss M. J. Rathbun.

BRACHYURA GENUINA.

OXYRRHYNCHA.

FAMILY MAMAIIDE.

1905. Mamaiida, Stebbing, S.A. Crust., pt. 3, p. 22, and Proc. Biol.

Soc. Washington, vol. xviii., p. 157.

In the restricted sense this family corresponds with Alcock's sub-family Maiinæ.

GEN. MAMAIA, Stebbing.

1905. Mamaia, Stebbing, S.A. Crust., pt. 3, p. 23, and Proc. Biol. Soc. Washington, vol. xviii., p. 157.

Under the above references the reasons for discarding the longaccepted generic name Maia and accepting the new form Mamaia are discussed at length. Under the old name an excellent definition of the genus is supplied by Alcock, Journ. Asiat. Soc. Bengal, vol. lxiv., pt. 2, pp. 237, 238, 1895, and Deep-sea Brachyura of the Investigator, p. 55, 1899.

MAMAIA QUEKETTI, n. sp.

Plate XXVII.

This species appears to make a near approach to the rare form named Maja (Maja) spinigera by de Haan (Crust. Japon., decas quarta, p. 93, 1839; pl. 24, fig. 4, Pisa (Paramaya) spinigera, 1837; and M. (Maja) spinig., Errata, p. 244, 1849). It differs in that the frontal spines are more divergent, and instead of one-fourth the length of the rest of the carapace only between a fifth and a sixth of that length. The lateral spines are also less than a fourth of the length named. In the middle line of the carapace there is a longitudinal series of conspicuous spines, three before the middle and three behind it, with a little transverse pair between the last two, whereas in de Haan's species there are in this series only two spines instead of five behind the middle. Moreover, in the present species at the middle there is a stout bifid spine, with apices placed transversely, of which there is no hint in de Haan's figure or description. The transverse pair of spines on the posterior margin of the carapace are here smaller and wider apart than those shown in de Haan's figure. The oblique set of spines on the branchial regions are also somewhat differently arranged.

The chelipeds of de Haan's species in the male are described by Ortmann (Zool. Jahrb., vol. vii., p. 51, 1893) as longer than the cephalothorax, palm flattened, otherwise formed as in the female. In the present species, represented only by the male sex, the chelipeds are stouter than the next limbs and as long; they have the elongate hand and fingers quite smooth, but the two preceding joints conspicuously roughened with lines of tubercles, not smooth as in de Haan's female specimen.

The conspicuous spine at the distal end of the merus or fourth joint in all the walking legs, clearly shown in de Haan's figure, and