CRUSTACEA OF THE MERGUI ARCHIPELAGO. 187 
The ischiopodites are armed anteriorly with a small, acute, 
. dentiform tubercle. The upper margin of the arms does not, or 
only indistinctly, terminate in an acute tooth or spine at the 
distal end ; the anterior margin is more or less dilated distally, 
according to the individuals, and it often presents a small denti- 
culate prominence, as in 8. teniolata and in S. Lafondi, but 
never a spine. The under margin of the arm is minutely tuber- 
cular. The external surface of this joint is transversely rugose, 
but the inner and under surfaces are perfectly smooth, the former 
presenting the ordinary rows of hairs. The upper surface of the 
wrist is tubercular and armed, at its internal angle, with a short, 
acute, denticulate, depressed tooth, both in the male and in the 
female ; this tooth is quite absent in S. sinensis and S. intermedia, 
and it is therefore a good character for distinguishing these 
Species. 
The hands of the male are very similar to those of S. inter- 
media. They are a little more than once and a half as long as 
high, and the proportion of the (horizontal) length of the 
fingers to the palm is nearly as 173: 15, the fingers being 
comparatively shorter in this species than in S. sinensis. The 
palm has a convex outer surface, and is everywhere closely 
covered with smooth granules; these granules appear a little 
smaller towards the rounded under surface of the hands, and 
some of them are arranged in a rather indistinct oblique row, 
about the middle of the outer surface, as in S. sinensis, S. in- 
termedia, S. teniolata, and S. tetragona, M.-Edw. Near the upper 
margin the granules are a little more acute, but the rest of the 
upper margin of the palm is quite similar to the outer surface, 
presenting no trace of pectinated ridges. The convex inner sur- 
face of the palm is covered with a few small, acute granules, but 
it has never the transverse granulated crest which characterizes 
S. sinensis and S. intermedia. The outer and the inner surfaces of 
the fingers are minutely punctate, but the rest is quite smooth ; 
the upper margin of the mobile finger is covered with very small 
acute teeth or granules, which are arranged irregularly until some 
distance from the tip. Similar small acute teeth occur also on 
the under margin of the immobile finger. The tips of the 
fingers are scarcely excavated, and their inner margins are rather 
feebly denticulate. 
As I have already observed, the hands of some male specimens 
are smaller than those of other specimens of an equal size. In 
