6o 



I . Euplax boscii (Audouin). 



1825. Macrophthalmiis boscii (Savigny) Audouin. Expl. planches Crust, d. I'Egypte, pi. 2, f. i. 



1843. Macrophthaltmis boscii Krauss. Siidafr. Crust., p. 40, pi. 2, f. 5. 



\%'^2. Euplax boscii H. Milne-Edwards. Ann. Sc. Nat. (3) t. 18, p. 160. 



1852. Cleistostotna boscii Dana. U.S. Expl. Exp., Crust., p. 3(3, pi. 19, f. 3. 



1858. Cliaenostoma orientale Stimpson. Proc. Ac. Nat. Sc. Philadelphia, p. 97. 



1858. Cliaenosloma crassiinanusi Stimpson. Ibid. p. 97. 



1873. Euplax (Chaenostoviaj boscii A. Milne-Edwards. Nouv. Arch. Mus. Paris, t. 9, p. 281. 



1880. Euplax boscii de Man. Notes Leyden Mus., v. 2, p. 71. 



1884. Euplax boscii Miers. Zool. Voy. "Alert", Crust., p. 540. 



1886. Euplax (Chaenostomaj boscii Miers. Rep. "Challenger", Brachyura, p. 252. 



1888. Euplax boscii de Man. Arch. Naturgesch., Jahrg. 53, i., p. 357. 



1894. Ei:plax boscii Ortmann. Denkschr. med.-naturw. Gesellsch. Jena, Bd 8, p. 58. 



1905. Euplax boscii Lenz. Abhandl. Senckenb. Gesellsch., Bd 27, p. 367. 



1906. Euplax (Ckaeuostoma) boscii Nobili. Ann. Sc. Nat., (9) t. 4, p. 319. 



1907. Chaenostoma orientale Stimpson, Smithson. Inst., Miscell., Coll., v. 49, p. 98. 

 1907. Chaenostoma crassiinanus'i Stimpson. Ibid. p. 98. 



1910. Euplax boscii Stebbing, Ann. S. A. Mus., v. 6, prt 4, p. 329. 



Stat. 86. Dongala, west coast of Celebes. 6 cf , 7 9- 



Stat. 131. Karakelang, Talaut Islands, i c?, 3 9 (o"^ of the latter with a parasitic Isopod in 



its left branchial cavity). 



Stat. 133. Lirung, Talaut Islands. 3 cf, 2 9 (^H juv.). 



Stat. 225=. Lucipara Islands, Banda Sea. 2 (j^, i 9 (^^ juv.). 



Stat. 231. Ambon. 2 9- 



Stat. 250. Kur Island. 2 c^ juv. 



On account of some discrepancy between the original descriptions of H. Milne -Ed\v.\rds 

 and D.\N'.\, Stimpson founded the genus Chaciiostoina for the reception of Dan.\'s species, 

 which he beheved to be distinct from the true "■ Macrophthahiius" boscii; for this reason the 

 name Chaenosloiim orientale was propo.sed. It is now generally agreed, that in reality this 

 latter is identical with Euplax boscii^ for the differences in the shape of the external maxillipeds 

 are variable, so that in some specimens the merus is much more distinctly shorter than the 

 ischium than is the case in others. 



I am inclined to regard "• Cliaenostoina" ci-assinianus Stimpson likewise as a synonym 

 of the present species. The author does not precisely enumerate its specific characters, but in 

 comparing his description with what may be observed in adult specimens of Euplax boscii, the 

 principal differences are, that there is only a slight emargination behind the outer orbital angle, 

 and that the eyes outreach these angles in E. crassimana. Stimpson's specimen is very small 

 (only 6 — 7 mm. across the carapace) and in .specimens of this and of smaller size I observed 

 exactly the very differences here enumerated. It was collected, moreover, at the same locality 

 as E. boscii (Loo-Choo Islands). 



De Man (1888) remarks, that this species attains a breadth of 15 mm. across the 

 carapace, but that a 9 of only 9 mm. breadth was bearing eorors. The ''Siboga"-material 



Metaplan. hirsiitimana, which was afterwards by the latter author (Rec. .\ustral. Mus., v. 9, n" 3, 1913, p. 321), on Miss Rathbun's 

 authority, recognized to be the same as E. tridentala. The specimens were taken by the Australian authors ia rather great quantities on 

 the mud-flats of Auckland Creek (Queensland) and of the mouth of the Paramatta River (New South Wales). 



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