CRUSTACEA OF THE MERGUI ARCHIPELAGO. 243 
(or median frontal tooth) is small, triangular, depressed, narrow 
and subacute, but projects nevertheless a little more forwards 
than the lateral frontal teeth, which are triangular and obtuse. 
The external angles of the anterior margin of the cephalothorax 
are rounded. Immediately behind the frontal margin a transverse 
roove is seen close and parallel to it, bordering pees the 
gastric region. 
The eye-peduncles are very slender and distinctly longer than 
the breadth of the anterior margin of the cephalothorax, being 
almost twice as long as the distance between the two lateral frontal 
teeth. The cornea is small, scarcely measuring a twelfth of 
the length of the peduncle: but in younger specimens it is com- 
paratively larger. The ophthalmic scales are narrow, dilated at 
their bases and armed at their distal ends with three or four 
acute teeth. The peduncles of the internal antenne in the 
adult are scarcely longer than the eye-peduncles. The antennal 
peduncles are a little shorter than the eye-peduncles and their 
penultimate and antepenultimate joints are hairy, the latter 
joint being armed above at its outer angle with a hairy spine, 
which projects a little beyond the anterior end of the penultimate 
joint. The terminal joint is about as long as the two preceding 
taken together and is a little compressed. The flagella of the 
outer antenne are naked. 
The abdomen has the ordinary structure and form. ‘The 
uropoda are asymmetrical and hairy along the margin of their 
terminal joint ; the left is the larger. The external foot-jaws are 
about as long as the internal antenne. The anterior legs are 
equal, and resemble those of Clibanarius longitarsis, de Haan. 
The slightly arcuate upper margins of the arms are unarmed and 
entire; the external margins of their under surfaces are armed 
at their distal ends with two small acute teeth, but their inner 
margins are unarmed and entire. The outer surfaces of the arms 
are covered with many short and small piliferous lines, their 
inner surfaces are nearly smooth and glabrous; and the smooth, 
unarmed under surfaces bear a few small tufts of yellow hairs. 
Similar hairs are also observed on the under surfaces of the basi- 
podites and ischiopodites ; their upper margins present also 
small transverse tufts of similar hairs. The upper margin of the 
wrist is armed, at its distal end, with a small, acute, dark-pointed 
spine, which is sometimes accompanied by a still smaller spinule 
16* 
