1 



2 



3 4 



d 



(? 



cT sex unknown 



23.5 



27.5 



33._ 30._ 



11.5 



13.— 



16.— 14.— 



3.5 



4.— 



— — 



18.— 



21.5 



— — 



8.5 



12.— 



— — 



168 ZOOLOGISCHE MEDEDEELINGEN — DEEL 1. 



Distance between tips of outer orbital angles 



Length of carapace 



Fronts in its narrowest place .... 

 Length of palm (immobile finger included) 

 Height of palm at insertion of mobile finger 



1 — 2 are specimens of the Museum, 3 is a specimen of Milne-Edwards, 

 4 a specimen (the sex of which is not stated) of Lenz (1905). 



M. dilatatus de Haan (PI. VI, Fig. 4). 



1835. Ocypode {Macrophthalmus) abbreviata de Haan. Fauna Japonica, 



Crust., p. 26 (nomen nudum). 

 1835. Ocypode {Macrophthalmus) dilatata de Haan. Fauna Japonica, 



Crust., p. 55, pi. 15 f. 3 ') (Japan). 

 1852. M. dilatatus H. Milne-Edwards. Ann. Sc. nat. sér. 3, Zool., t. 18 



p. 157 („Mers du Japon et de l'Inde"). 

 1890. „ dilatatus de Man. Notes Leyden Museum, v. 12. p. 76, pi. 4 f . 9 



(no new record). 

 1894. „ dilatatus Ortmann. Zool. Jahrb. Abt. Syst., Bnd. 7 p. 744 



(Tokio Bay). 

 1897. „ dilatatus Ortmann. Zool. Jahrb. Abt. Syst., Bnd. 10 p. 345 



(south-east coast of Japan). 

 1904. „ dilatatus? Doflein. Wiss. Ergebn. „Valdivia" Exp., Bnd. 6, Bra- 



chyura, p. 29 (Padang). 



This species closely resembles M. carinimanus and in the case of 

 female specimens the discrimination of both species may be often impos- 

 sible; in M. dilatatus however the carapace is somewhat less broad, the 

 outer orbital angle is smaller than the anterior lateral tooth of the cara- 

 pace (in M. carinimanus both teeth are of nearly equal size), the incision 

 between them is narrow and deep and the upper orbital border is not 

 so strongly curved as in the species of Milne-Edwards. The granulation 

 on the carapace is much more conspicuous than in the preceding species. 

 The chief difference is to be found in the palm of the male cheliped, 

 which is already well figured by de Haan and again by de Man; the 

 latter author has clearly shown its principal features. Along the upper 

 border there is a row of rather large, spiniform tubercles, widely sepa- 



1) Not f. 2 as is mentioned in the text and copied by H. Milne-Edwards. 



