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The animal is of a reddish-yellow colour, with irregular, large, reddish blotches on the 



anterior half of the carapace. 



Dana records the species from New South Wales or Xew Zealand, the exact locality 

 being apparently unknown. Ortmanx mentions tw^o specimens from Tahiti, but unfortunately 

 he o-ives no description. If my determination be right, the species also occurs at Lombok. From 

 H. latrcWi it is certainly distinct, though it is closely related to that species. 

 Dimensions in mm. : 



Distance between external orbital angles \2.- — 



Ma.ximuni breadth of carapace 13-5 



Length of carapace IO-75 



Posterior margin of carapace 7.5 



Length of cheliped 21. — 



Horizontal length of chela 9.5 



Height of palm : ■ 6. — 



Length of movable finger 5.5 



Breadth of 3d segment of abdomen 6.7 ') 



Length i . , . , 1 -'2 ') 



„ , , , ! of o"> segment of abdomen . . ( ,, 



Breadth at base ) ( 3-3 ) 



Length ) i 1-65 ') 



„ ' , , , /of terminal segment of abdomen \ „ ,, 



Breadth at base \ " | 1.8 ') 



Chasmagnathus de Haan. 



iS'35. Chasmagnathus de Haan. Faun. Japon., Crust., p. 27. 



This genus is distinct from Helicc by the postero-lateral margins of the carapace being 

 convergent and the antero-lateral margins divergent backward, by a generally broader shape 

 of the abdomen of the cf, by the palm of the chelae being longer than high, and by the 

 merus of the external maxillipeds being nearly half as broad anteriorly as long and much 

 more elongate than in Helicc. 



Thus restricted the genus includes only the well-known Japanese species Ch. convexiis 

 de Haan -). Now Herklots in his Symbolae carcinologicae ^), that deal with the collection of 

 Crustacea in the Leiden Museum, mentions two new species; C/i. giddosns de Haan M.S. 

 trom Java, and one, unnamed, from Abessynia. The latter species I have not found back; 

 C/i. giddosus is represented by three specimens (all 9, dried), one of which is a new species 

 of Sarmatiiim {fryatti), already described in my paper on Scscir/;/a etc. *) and the remaining 

 specimens undoubtedly belong to C//. convexiis. The locality (Java, Kuhl et van Hasselt coll.) 

 seems to me to be probably erroneous, and perhaps the two specimens of C/iasmagnat/ms 

 have been mislaid. 



1) Measured under microscope. 



2) Ocypodc (Chasmagnathus) convcxiis de Haan, Faun. Japon., Crust., 1835, p. 56, pi. 7, f. 5; Adams et White, Zool. Voy. 

 ••Samarang" 1850, p. 52; Chasmagnathus convexiis H. Milne-Edwards, Ann. Sc. Nat. (3) t. 20, 1853, p. 200; Ortm.\nn, Zool. Jahrb., 

 Syst., Bd 7, 1894, p. 727; Stimpson, Smithson. Inst., Miscell. Coll., v. 49, 1907, p. 133. Hab. Japan and Loo-Choo Islands. The species 

 described by H.-vswell under this name (Cat. Austral. Crust., 1S82, p. 106) is, as Ortmann rightly remarks, gertaicly diflerent from that 

 of DE Haan, aud it cannot even be traced to which genus it should belong. 



3) Tijdschr. Entomol., t. 4, 1861, p. 128. 



4) Zool. Med. Mus. Leiden, v. 3, 1917, p. 216, textfig. 6. 



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