CETTSTACEA. 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 Eossmann, 

 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 Misodes, 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 sinuated as in Leptodiuslividus; 

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

 lateral marginal teeth ; the carapace is slightly 1 obulated 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 mger (ForsJcal). 



A single female of |his very common Oriental species was obtained 

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



A specimen is in the British Museum from Port Jackson (Cwmm^r). 



O. 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 iu the collection of the British Museum from Egypt 

 (Col. J. Burton); the Gulf of &uez (B. MacAndrew) ; Eed Sea, 

 Dsedalus Shoal (Lt.-Col. Play fair); El Tor {Major MacBomld).; 

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

 Balahac Straits (Smithsonian Institute, Wilkes Expedition) ; New 

 Guinea (Dr. Bleehers Coll.) ; Philippine Islands, Guimaras (Guming), 

 designated C. hirtipes by Adams and White ; Keeling or Cocos 

 Islands (Lt. Durnaby, 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, froin which it is 

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

 with more acute areolse 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. nigerf. 



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

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



