’sRIJKS MUSEUM VAN NATUURLIJKE HISTORIE — LEIDEN. 143 
Ortmann (Zool. Jahrb. Syst., Bd. 10, 1897, p. 333) identifies this 
species with S. reticulata Say, the type species of the genus, but Miss 
Rathbun regards it as a distinct species, though very closely related to 
that of Say; indeed, in her key to the American Sesarmae (Proc. Biol. 
Soc. Washington, v. 11 p. 89) the only difference given between the 
two species is, that in S. cwracaoensis the eyes reach the outer orbital 
angle, whilst in S. reticulata they do not. De Man’s figure however does 
not show this length of the eye-stalk, nor did I detect it in his typical 
specimen, preserved in the Museum. 
31. Sesarma (Holometopus) dehaani H. Milne-Edwards. 
1835. Grapsus (Pachysoma) quadratus de Haan (nec Fabricius). Fauna 
Japon. Crust., p. 62, pl. 8 f. 3 — Japan. 
1853. Sesarma dehaani H. Milne-Edwards. Ann. Sc. nat., (3) t. 20 p. 184 
— Japan. 
1858. Sesarma dehaani Stimpson. Proc. Ac. Nat. Se. Philadelphia, 1858, 
p. 106 — Bonin Islands, Hongkong and Simoda. 
1865. Sesarma dehaani Heller. Crust. Reise , Novara’’, p. 62 — Shanghai. 
1887. Sesarma dehaani de Man. Zool. Jahrb. Syst., Bd. 2 p. 642 — no 
| new locality. 
1893. Sesarma dehaani Bürger. Zool. Jahrb. Syst, Bd. 7 p. 615 — 
Yokohama. | 
1894. Sesarma dehaani Ortmann. Zool. Jahrb. Syst., Bd. 7 p. 718 — 
Tokio, Nagasaki and Loo-Choo Islands. 
1907. Sesarma dehaani Stimpson. Smithson. Inst. Miscell. Coll., v. 49 
p. 134 — Bonin Islands, Whampoa (China) and Simoda (Japan). 
Specimens in the Museum: 
4 G', 19, Japan (type and co-types of de Haan). 
2, Kobe (Japan), v. Oordt v. Lauwenrecht coll. 1906. 
De Haan’s excellent figure of this species has enabled us to recog- 
nize it perfectly well, but as his description is somewhat short, I shall 
here try to make the S. dehaani better known. The carapace is regularly, 
but not strongly, convex in a longitudinal direction, nearly straight 
transversely, but, as usual, declivous along the branchial regions. The 
distance between the outer orbital angles is equal to the length of the 
carapace in the median line, but as the lateral sides are curved outward 
in their anterior third, the greatest breadth of the carapace (lying at 
the outer end of the anterior transverse line on the branchial regions, 
which latter are very strongly declivous) distinctly exceeds its length. 
As Ortmann rightly remarks all specimens show a trace of an epibran- 
