382 
each other than those of the posterior pair. — The anal plate is 
somewhat saberrant: it is about as long as broad, very shortly ovate 
with the narrow portion posteriorly; a very short, setiform and 
slightly clavate branch originates on the lower side of the plate 
near the lateral margin somewhat from the end, and the result is 
that the plate projects as a rounded lobe between the branches. 
Legs. They are short and increase only a little in length po- 
steriorly. The last (eighth) pair is shown in fig. 2d,- but the 
animal being immature, its systematic value is rather slight; I 
shall only point out that the seta on the tibia is not half as long 
as its joint. 
Length. The specimen is :56 mm. 
Locality. Isl. Koh Chang (Gulf of Siam), under stones, 
Jan. 7. 1900 (Dr. Th. Mortensen leg.). 
Remarks. In adult specimens the upper antennal branch is 
probably a little more elongated and the tactile setæ present åa 
different. relative length. But other features in the structure of the 
antennæ, in the length and distribution of the dorsal hairs on the 
anal segment and especially the shape of the anal plate present 
together a sufficient number of characters for this species, which 
is more related to P. danicus and P. elegantulus than to any of 
the species described below. 
Species 12. It can be seen on the plates that I had origi- 
nally inserted this curious species in another place. But I believe 
now that it may be more properly placed here as a separate group. 
By the structure of the anal segment, the arrangement of its dorsal 
hairs, the shape of the anal plate, ete. it differs widely from all 
other species known to me. 
12. Pauropus Mortensenii n. sp. 
Pl. IV, fig. 6a—65, pl. V, fig. 1a—1 c. 
Material. I have examined five specimens: two are adult 
females, one is an adult male, one is a specimen with eight pairs 
