CRUSTACEA OF THE MERGUI ARCHIPELAGO. 139 
As in Dotilla, the cephalothorax is more enlarged above the 
bases of the legs than at its upper surface; and it is rather 
thick, though not globose. The upper surface is broader than 
long, the proportion of the greatest width, which is found a 
little behind the middle, being to the length (the front included) 
as 7:5. The upper surface is rather flattened, being only 
slightly declivous towards the front, towards the postero-lateral 
angles and behind a straight elevated transverse line which pro- 
ceeds at a short distance from, and parallel to, the posterior margin 
between the bases of the last pair of legs. The posterior 
margin is slightly concave in the middle, and its lateral angles 
are rounded. | 
The upper surface is smooth and almost glabrous, presenting 
only a few scattered short cilia on the postero-lateral regions ; 
the remarkable grooves of the genus Dotilla are quite wanting. 
Besides the broad, though shallow, longitudinal median furrow 
of the front, some interregional grooves are faintly indicated. 
Thus an impressed transverse line, interrupted in the middle, 
lies quite on the middle of the cephalothorax, and this I regard 
as the ordinary transverse groove which separates the gastric 
from the cardiac region; behind this groove a second is some- 
times observed, situated as far from the transverse line above 
described as the latter is distant from the posterior margin 
of the cephalothorax. This second impressed line is apparently 
that which separates the anterior cardiac region from the poste- 
rior. The branchiocardiac grooves are shallow and very faintly 
marked. Though the upper surface is smooth and flattened, it 
appears, however, somewhat uneven on the branchial regions, 
owing to the occurrence of four or five small prominences, the 
posterior of which is a little more distinct than the others, and 
assumes the character of a small short transverse tubercle lying 
close to the base of the legs of the last pair, near the postero- 
lateral angles of the upper surface. Two slight transverse 
prominences are also observed on the anterior cardiac region. 
The front is a little broader than in the species of the genus 
Dotilla, measuring between the eye-peduncles about a fourth 
of the distance between the external angles of the orbits. The 
anterior margin is slightly triangular, being a little prominent 
and subacute in the middle, whereas the lateral angles are 
rounded. The front is rather much declivous, and presents a 
broad, though shallow, longitudinal median furrow. The orbits 
