CRUSTACEA OF THE MERGUI ARCHIPEDAGO. 181 
Section D.—Sesarme the cephalothorax of which is armed ~ 
with one or two epibranchial teeth behind the extraorbital 
tooth, and in which the palm of the anterior legs of the 
male is not armed with two oblique, parallel, minutely pecti- 
nated ridges. 
This Section is represented in the Indo-Pacific Region by a 
rather large number of species, some of which it is difficult to 
distinguish. 
99. SESARMA THNIOLATA, White. 
Sesarma teniolata, White, List Crust. Brit. Mus. p. 38 (1847); Miers, 
Crustaceans from Duke-of-York Island, Proc. Zool. Soc. 1877, p. 137 
(footnote). 
Sesarma tzeniolata, de Man, Notes from the Leyden Museum, vol. ii. 
p. 26. 
Sesarma Mederi, Milne-Edwards, Ann. Sct. Nat. t. xx. p. 185 (1853). 
Three fine male specimens were collected. In all these 
examples the upper surface of the cephalothorax is densely 
covered with small tufts of hairs. 
Sesarma teniolata, White, is closely allied to Sesarma Lafond, 
Hombr. & Jacq., the cephalothorax and the ambulatory legs in both 
species being similar. The former, however, may be distin- 
cuished at first sight by the longitudinal pectinated ridge on the 
upper margin of the palm of its chelipedes, and by the occur- 
rence of a longitudinal transversely striated ridge on its mobile 
finger. These two species differ from many other species of 
this section, in which the distance between the extraorbital 
teeth is greater than the length of the cephalothorax (as, e. g., 
from 8. tetragona, 8. rotundifrons, 8. intermedia, S. sinensis), by 
the upper margin of the arms of their anterior legs terminating 
in a strong acute tooth at its distal end, and by the anterior 
margin being armed with a prominent denticulated tooth. 
S. teniolata serves to connect this section of the genus with the 
preceding, as the upper margin of the palm of the anterior legs 
is furnished with only a single pectinated ridge. 
A careful examination of a typical specimen of S. Mederi in 
the Museum of Paris convinced me that this species is identical 
with S. teniolata, White. Although the latter name has priority, 
the first description of this species was published by Milne- 
Edwards. 
