OEUSTACEA OE THE MEEGTJI AECHIPELAGO. 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 iadividuals, and it often presents a small denti- 

 culate prominence, as in S. tceniolata 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 thie inner and under surfaces are perfectly smootb, 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 8. 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 V7\ : 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, 8. tceniolata, and 8. tetragona, M.-Edw. JSTear 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 8. 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 



