CRUSTACEA OF THE MERGUI ARCHIPELAGO. 143 
length ; the inner edge of the mobile finger is, moreover, a little 
prominent along its proximal half, presenting a low longitu- 
dinal tooth, which is a little more coarsely crenulate at its base. 
The inner edge of the immobile finger does not present such a 
tooth or prominence, but a small incision quite at the base. The 
tips are acute, pointed, and slightly curved, crossing one another 
when closed. 
The ambulatory legs are rather slender, and resemble those 
of the species of the genus Helecius. Those of the third pair, 
the antepenultimate legs, are the longest; those of the last 
pair the shortest of all. The meropodites are strongly com- 
pressed and flattened on their upper and under surfaces, and do 
not present the remarkable “tympana” of Dotilla and Scopi- 
mera; in the latter the tympana constitute oval impressions 
which are bordered by a wall of the more elevated portion of the 
surface of the joint. A histological examination of the legs might 
nevertheless prove their existence also in our Diowxippe; for 
when studying the upper surface of these joints by means of a 
magnifying-glass I observed oval lines bordering the central 
flattened part. The meropodites have minutely granulated 
upper and under margins, but are for the rest unarmed. 
The other joints are smooth and unarmed; the propodites are 
also compressed. The dactylopodites are a little shorter than 
the propodites, are laterally compressed, and acute. The ambu- 
latory legs are also nearly glabrous; the dactylopodites are, 
however, a little hairy along their margins, and the legs of the 
second and third pair present a dense hairy down at the articu- 
lation of their carpopodites with the propodites, along the upper 
margins and on the upper and the under surfaces of these 
joints. 
Dimensions of the largest male specimen :— 
millim. 
Length of the cephalothorax (without.the epistome) .. 4° 
Distance between the upper external orbital angles .. 641 
Greatest width of the upper surface of the carapace .. 62 
Wenethvor the anterior legs... - 1.6... ne eens ee ee 21 
[Liiheiula (OLE 11g N16 ear nar a ae 83 
Height of the palm .............. se eee seers eee ee 34 
The greatest width of the upper surface of the cephalothorax 
of the ova-bearing female is scarcely 5 millim. 
