CRUSTACEA. 215 



A complete revision of the genus would be necessary, based upon 

 the comparative study of types and of a much larger series of 

 specimens than the Museum at present possesses, in order to deter- 

 mine the real value of the characters ascribed to several of the 

 species, which I think will be shown hereafter to be merely syno- 

 nyms of earlier-described forms. (See on this question Kossmann, 

 Zool. Ergeb. roth. Meer. pp. 32, 33, 1877.) 



Two very small males obtained on the beach at Thursday Island 

 (second collection, No. 167) are apparently intermediate in many 

 characters between this genus and Etisodes, which they resemble in 

 general appearance. The basal antennal joint enters the inner 

 orbital hiatus, but the flagellum is just excluded from it, and the 

 carapace is broader than in Etisodes and is shaped as in Leptodius; 

 the frontal lobes are truncated, not sinuatcd as in Leptodius lividus; 

 the anterior margin straight : there are five distinct acute antero- 

 lateral marginal teeth ; the carapace is slightly lobulated and granulated 

 anteriorly, plane and smooth posteriorly ; the carpus and palms of 

 the chelipedes rugose ; the ambulatory legs somewhat compressed. 

 Length of carapace barely 4 lines. 



47. Chlorodius niger (Forslcal). 



A single female of this very common Oriental species was obtained 

 at Port Denison in 4 fms. (No. 111). 



A specimen is in the British Museum from Port Jackson {Cuming). 



C. niger ranges from the Red Sea and the Mascarene Islands 

 eastward through the Indian Ocean and Malaysian archipelago to 

 the islands of the Pacific (Samoa and Sandwich Islands). 



Specimens are in the collection of the British Museum from Egypt 

 (Col. J. Burton); the Gulf of Suez (11. Mac Andrew) ; lied Sea, 

 Dasdalus Shoal (Lt.-Col. Playfair); El Tor (Major MacDonald); 

 Seychelles (Dr. E. P. Wright); Ceylon, Galle (Dr. W. Ondaatje); 

 Balabac Straits (Smithsonian Institute, Wilkes Expedition) ; New 

 Guinea (Dr. Bleekers Coll.); Philippine Islands, Guimaras (Cuming), 

 designated C. hirtipes by Adams and AVhite : Keeling or Cocos 

 Islands (Lt. Bumaby, R.N.) ; Samoa Islands, Upolu (Rev. S. J. 

 Whitmee), and Sandwich Islands (W.H. Pease). 



Perhaps the Chlorodius rufescens, Targioni-Tozetti *, from Java, 

 should be added to the synonyma of this species, from which it is 

 distinguished by its author by the longer, more convex carapace, 

 with more acute areolae and marginal lateral teeth. MM. A. M.- 

 Edwards and De Man have noticed considerable variation in the 

 degree of acuteness of the antero-lateral marginal teeth and adjacent 

 tubercles in C. niger f . 



* ' Crostacei delta Magenta,' p. 43, pi. iv. figs. 6-8, 10-12, 14, 18 (1877). 

 t Vide ' Notes from the Ley den Museum,' ii. p. 174 (1880). 



