170 DR. J. G. DE MAN ON THE PODOPHTHALMOUS 
between the external orbital angles to the length of the cephalo- 
thorax is as 20:164, in 8. quadrata, Fabr.,=ungulata, M.-Edw., 
=affinis, de Haan, as 20:154. In the proportion of the distance 
between the external orbital angles to the breadth of the front, 
S. aspera completely agrees with 8. guadrata, Fabr. The penul- 
timate joint of the male abdomen has a somewhat different form, - 
being smaller than in S. guadrata, Fabr. The legs of both 
species almost completely agree with one another, the only 
differences observable being the following :—The oval transverse 
tubercles, which occur on the upper margin of the mobile finger 
of the male, number 16 or 17 in S. aspera, whereas in the 
typical specimen of S. guadrata there are only 11-18, of 
which the proximal 7-9 tubercles are more distinct than the 
others. 
The species of this section seem to be comparatively rare, for 
few specimens exist in museums; but when a more extended 
series 1s available for comparison, I am disposed to believe that 
the differences I have indicated will be found to be individual. 
The Leyden Museum contains only a single male specimen from 
an unknown locality ; this specimen has 12-13 tubercles on the 
mobile finger, and certainly belongs to the true S. guadrata, 
Fabr. ; it was, however, referred by me to S. affinis, de Haan, 
when I worked out the Leyden collection. Sesarma aspera 
with 17 tubercles on the mobile finger, 8. guadrata with 11-18, 
S. ungulata with 8, and S. affinis with 7, are, I think, mere 
local or perhaps only individual varieties of one and the same 
species (S. guadrata, Fabr.). 
Sesarma aspera, Heller, has been recorded from Ceylon, Madras, 
and the Nicobar Islands. 
93. SesanMa Metissa *,n. sp. (Pl. XII. figs. 5-7.) 
One male specimen was collected in Kisseraing Island. This 
species agrees almost completely in all its characters with Heller’s 
Sesarma aspera, and differs from it only by the different form of 
the prominences with which the upper margin of the mobile finger 
is armed, by its somewhat more slender ambulatory legs, and by 
the dactylopodites being comparatively a, little shorter. 
In the structure and dimensions of the cephalothorax, and in 
the form of the front and of the male abdomen, both species are 
alike. 
* Melissa, thedaughter of Oceanus. 
