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Carapace widened proximally (lateral margins distinctly 

 convergent backward). Inner orbital lobe coalesced with 

 the front over nearly the whole inner margin, sharp 

 and keeled M. messor Forskal 



4. Front broader, orbits smal! M. eydouxi H. Milne-Edwards 1 ) 



Front narrower, orbits wide M. thukuhar (Owen) 



5. Lateral margins of carapace much convergent backward; 



distance between external orbital angles to length of 

 carapace as 100 : 84 — 87°/ o in small and medium-sized 



and 100 : 89 — 92°/ o in large specimens M. latifrons (White) 



Lateral margins of carapace less convergent backward; 

 distance between external orbital angles to length of 

 carapace as 100 : ± So°/ o M. maculatus H. Milne-Edwards 



6. Postfrontal lobes litt4e prominent; front not strongly de- 



clivous; internal orbital lobe broad and rounded at tip, 

 coalesced with the front along a short distance (as in M . 

 thukuhar). Dactyli of walking legs only slightly shorter 



than propodites M. quadridentatus Stimpson 3 ) 



Postfrontal lobes more distinct and sharply separated; front 

 strongly deflexed ; internal orbital lobe narrow and acute 

 at tip, coalesced with the front along greater distance 

 (as in M. messor). Dactyli of walking legs much shorter 

 than propodites M. oceanicus (Jacquinot et Lucas) 



1. Aleiopograpstts messor (Forskal). 



Literature: AlXOCK, 1. c. p. 397. Description: DE MAN, Journ. Linn. Soc. London, v. 22, 

 1888, p. 144, pi. 9, f. ii; Arch. Naturg., Jahrg. 53, 1., p. 361, pi. 15, f. 6. 



Grapsus (Pachygrapsus) aethiopicus 3 ) Hilgendorf. v. d. Decken's Reis. Ost-Afrika, Bd 3, 1., 

 Crust., 1869, p. 88, pi. 4, f. 2. 



Stat. 47. Bay of Bima, Sumbawa. 12 rf (mostly juv.), 1 9 witl1 e gg s - 

 Stat. 71. Macassar. 1 rf. 



Miers *) described a subsp. frontalis from Macassar and other localities, which seems to 

 be an individual variation and has not been maintained by subsequent authors, 



Another subspecies {gracilipes) has been founded by de Man 5 ), originally from the 



1) Ann. Sc. Nat. (3) t. 20, 1853, p. 165. It must be admitled, that ihe differences between this specie» and M. thukuhar are 

 insignificant, and Kingsi.ev already identified both ïpecies with M. mester; the sarae has been done in recent years by Miss RATHBUN 

 (Buil. U.S. Fish Comm. Tor 1903, v. 23, prt 3, 1906, p. 839) in dealing with the marine Biachyuia and Macrura of the Haivaiian Islands. 

 It is from this very locality that both M. eydouxi and .1/. thukuhar originate. 



2) Description: pe Man, Zool. Jahrb., Syst., Bd 9, 1895, p. 76, Bd 10, iSgS, pi. 28, f. 16. 



3) Even in recent days the species has been referred to under this name by Doflein (Wiss. Erg. Tiefsee-E.\p. "Valdivia", Bd 6 

 (Crust.), 1904, p. 130. and implicitly ranged with P tus. With the name Metofografsus messor the author is apparently unacquaiuted. 



4) Ann. Mag. Nat. Hist. (5) v. 5, p. 311; Rep. "Challenger", Biachyuia, 1SS6, p. 258. 



5) Notes Leiden Mus., v. 13, 1891, p. 49, pi. 4, f. 14. 



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