Arctus Martensii A. Ortmann, in: Zoolog. Jahrb. Abth. f. Syst. VI, 1891, p. 44. 



Scyllarus Martensii L. A. Borradaile, in: The Fauna and Geography of the Maldive and 



Laccadive Archipelagoes. Vol. II, Pt. 3. 1904, p. 754, PI. LVIII, fig. 4. 

 Scyllarus Martensi G. Nobili, in: Bollet. Mus. Torino, Vol. XVIII, 1903, p. 12. 

 Scyllarus martensi M. J. Rathbun, The Brachyura and Macrura of the Hawaiian Islands. 



Wash. 1906, p. 896, PI. XVIII, fig. 2. 

 Scyllarus martensii H. Balss, Ostasiatische Decapoden. II. Die Natantia und Reptantia, München 



1914, p. 79. 

 Scyllarus arctus, var. W. de Haan, Fauna Japon. Crustacea, 1841, p. 154, PI. XXXVIII, 



fig. 2 (second variety). 



Stat. ^2>. March 2426. Bay of Pidjot, Lombok. 22 m. Bottom : mud, coral and coralsand. 



2 ova-bearing females. 

 Stat. 64. May 4/5. Kambarigi-bay, Tanah Djampeah. Up to 32 m. Bottom: coral, coralsand. 



1 young male and 1 young female. 



Stat. 71. May 10 — June 7. Makassar. Up to 32 m. Bottom: mud, sand with mud, coral. 



2 young males. 



Stat. 104. July 2/3. Sulu-harbour, Sulu-island. 14 m. Bottom: sand. 2 young females. 



Stat. 164. August 20. i°42'.5 S., 130° 47'. 5 E. 32 m. Bottom: sand, small stones and shells. 



2 males. 

 Stat. 313. Febr. 14/16. Anchorage East of Dangar Besar, Saleh-bay. Up to 36 m. Bottom: 



sand, coral and mud. 4 females, 2 of which with eggs, and 2 males. 



Though these males and females belong, no doubt, to one and the same species, they 

 show, however, some slight differences from one another, certainly because they have been 

 collected at so remote localities of the Archipelago. The variability of Scyll. Martensii is at 

 once established by the fact that two type specimens of this species from the Hamburg Museum, 

 which Prof. Pfeffer has kindly sent me, even not fully agree with one another! One of 

 them, a female without eggs, 22 1 /;, mm. long from the frontal margin to the end of the telson, 

 is unfortunately of an unknown locality, the other, a little smaller, is an ova-bearing female, 

 on the label of which stands the name of "Amur", but, as Prof. Pfeffer wrote, this name does 

 only indicate that this specimen has been taken on the way from Hamburg to the Amur, so 

 that it may perhaps have been captured in the Indian Archipelago ! The incisions which separate 

 from one another the lobes on the anterior margin of the distal antennal squame, are distinctly 

 longer i. e. deeper in the female without eggs than in that with the label "Amur", so that the 

 lobes appear slightly longer and narrower. In this species the tergum of the i st abdominal 

 somite is elegantly divided by a set of longitudinal ribs in small areolets: in the larger female 

 these ribs run a little more oblique with regard to the posterior border than in the other 

 specimen. The i st external lobe of the distal squame of the outer antennae is marked in the 

 ova-bearing female with a black fleck, that does not exist in the other. In view of these 

 differences I propose to regard the larger female without eggs as the typical form of this species 

 and the other as a variety. 



The larger female with eggs from Stat. 33 is 36 mm. long, from the anterior margin 

 of the distal squame to the end of the telson : it is the largest specimen and will therefore be 

 described. Measured in the middle line, the carapace appears to be 11 mm. long and the 

 abdomen 19 1 /., mm.; the antero-lateral angles are 12 mm. distant, so that the carapace appears 



