
’s RIJKS MUSEUM VAN NATUURLIJKE HISTORIE — LEIDEN. 185 

88. Sesarma (Sesarma s.s.) ophioderma Nobili. 
1901. Sesarma (Sesarma) ophioderma Nobili. Boll. Mus. Torino, t. 16 
n°, 415 p. 44 —. Esmeraldas (Ecuador). 
89 
Sesarma (Sesarma s.s.) palawanensis Rathbun. 
1914. Sesarma (Sesarma) palawanense Rathbun. Proe. U. S. Nat. Mus., 
v. 47 p. 72 — Palawan Island (Philippines). 
~ Specimens in the Museum: 
1 9, New Guinea, Macklot coll. 
eke Bigs 2: 
Among the dried Crustacea of the Museum I found a very old  spe- 
cimen, collected by Macklot in New Guinea, which seems to be most 
likely referable to the species recently described by Miss Rathbun, though 
the determination must remain uncertain, as no figure has been as yet 
published. 
This species belongs to the same natural group as Ses. tetragona 
Fabricius, Ses. taeniolata White and Ses. lafondi Hombron et Jacquinot. 
The carapace is much flattened, shining and smooth, though 
the postfrontal lobes, the mesogastric and the posterior cardiac region 
are well marked off. The whole surface is covered with numerous greyish- 
white spots, surrounded by a brown ring, which spots during life pro- 
bably marked the insertion of tufts of hair; they are largest on the 
proto- and mesogastric region. 
From Ses. taeniolata, to which the present species, as Miss Rathbun 
remarked, is most nearly allied, it is distinguished 7a. by having a 
narrower (longer) carapace and by the breadth of the front being less 
than half the distance between the external orbital angles (in Ses. ftue- 
niolata it is constantly more than half this distance). If we take the 
distance between the external orbital angles = 100, than the length of 
the carapace in the median line is in Rathbun’s specimen = 94.7, the 
breadth of the front — 48.6; and in the specimen of the Museum these 
proportions are respectively 93.2 and 48.5. 
In 5 specimens of Ses. taeniolata of different size the length of the 
carapace in °/. of the distance between external orbital angles is respec- 
tively: 93.0, 87.6, 88.1, 90.6 and 91.0; save in the first instance this 
proportion is thus always distinctly less than in Ses. palawanensis, and 
in the only exception the proportion is about equal to that of the Museum 
specimen of Rathbun’s species. The breadth of the front is in Ses. twentolata 

13 
(28—V1I—1917). 
