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LitOCheira Kinahan. 



1858. Litoclieira Kinahan. Journ. Roy. Dublin Soc, v. i, p. 121. 



1880. BracJiygrapsns Kingsley. Proc. Ac. Nat. Sc. Piiiladelphia, 1880, p. 203. 



1900. Litoclnra Alcock. Journ. As. Soc. Bengal, v. 69, prt 2, p. 314. 



The members of this genus are all very smal! and characterized, as has been rightly ' 

 j)Ut foith by Alcock, by the front being turned down and arched, never lamellar and square- 

 cut, mostly, if not always, bilobed anteriorly, and by the very long silky setae, fringing 

 not only the cara p ace, but also the chelipeds and the walking legs. A row 

 of very long setae is nearly always inserted across the front and continued on the eye-stalks; 

 the carapace is mostly covered with shorter or larger hairs, but may be also naked and 

 covered with granules ; the various regions are indistinct ; the chelipeds short. 



The type of the genus which now includes even more species than Carcinoplax^ is 

 L. bispinosa Kinahan, an apparently common species of Australia and propably also occurring 

 at New Zealand. All species are found in shallow waters. 



Alcock divides the genus into two groups; one in which the carapace is broader than 

 long, "as in Kinahan's type", ') and another, in which it is nearly square. The material of the 

 "Siboga", however, renders it impossible to maintain this mode of dividing the species, as 

 there are gradual transitions. 



The "Siboga" expedition yielded 6 species, 3 of which are new. 



Key to the species : 



1. Antero-lateral margins of carapace distinctly toothed ... 2 

 Antero-lateral margins of carapace entire, faintly notched or 



inconspicuously angular behind external orbital angle . . 10 



2. Antero-lateral margins of carapace with 4 teeth in all; the 



external orbital angle is a broad, sharply-edged plate and 



incompletely fused with the next tooth, the two folio wing 



ones are depressed, truncate and the last is small and 



subacute. Greatest breadth of carapace 1.4 times the length, 



the latter dimension equal to extent of fronto-orbital border L. ciliata (Stimpson), 



a}ig7istifrons Alcock, 

 cristata Rathbun ") 

 Antero-lateral margins of carapace with less than 4 teeth in all 3 



:) The type species is, however, according to Mc Culloch's figure (Ree. .\ustral. Mus., v. g, n" 3, 1913, p. 324, textfig. 42), 

 bui very little broader than long. 



2) Pilumnoplax ciliata Stimpson, Proc. Ac. Nat. Sc. Philadelphia, 1S58, p. 94: Smithson. Inst., Miscell. CoU., v. 49, 1907, 

 p. 92. Hab. Simoda (Japan). 



Litochira angiislifrons Alcock, Journ. As. Soc. Bengal, v. 69, prt 2, 1900, p. 315; Borradaile, Fauna and Geography Maldive 

 and Laccadive Arch., v. i, 1903, p. 430. Hab. Bombay, Karachi and Male AtoU. 



Litochcira cristata Rathbun, Proc. Biol. Soc. Washington, v. 22, 1909, p. Ili; K. Dansk. Vid. Selsk. Skr., 7. Raekke, .Afd. 5, 

 n" 4, 1910, p. 340, fextfigs 25 — 26. Hab. Gulf of Siam. 



These three species seem to have so much in common, that they may be perhaps really identical. In Alcock's and Miss 

 Rathbun's species the greatest breadth of the carapace is 1.4 times its length, in Stimpson's L. ciliata considerably more (1.58 times its 

 length) but on the other hand in L. ciliata the meropodites of the walking legs are crested anteriorly, in the same way as in L. cristata^ 

 in which, however, the crest of the last legs is found posteriorly; ogain these two species agree in having the arm of the chehped sharply- 

 edged and prominent near its distal end. Such mutual relations support the probability of the three species being really identical. 



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