184 E. A. ANDREWws, 
be expected in a new formation; the usual sharp pointed terminal 
segment of the legs is here opposed by a rude process, thumb, 
grown up from the distal end of the penultimate segment, as seen 
in Fig. C. The sharp pointed finger is bent at the tip and 
hollowed out on the inner face, distally, where it meets the opposing 
thumb. It is specialized as a slightly hollowed pad bounded by an U 
shaped brush of setae comparable to that on the distal part of the 
claw of Panulirus. The blunt thumb is hollowed out as a lower 
beak, or spoon, as in Panulirus. The claw is thus essentially similar 
to that in Panulirus with the gross exception that the part opposing 
the thumb is not set off as a special process of the distal segment 
of the leg. 
On eutting sections of this claw we see the same specializations 
as in Panulirus. While both thumb and finger have small scattered 
brushes of setae upon the proximal parts of the opposed faces it is 
only the finger and not the thumb which bears a specialized U 
shaped brush along the edges within the bounding rim of the gape, 
as is represented in Fig. D, where the distal finger is above and 
the thumb below. On the thumb also there are small setae but 
these are not so sharply restrieted to the edges but more diffuse. 
In general the brushes of both thumb and finger are less narrow 
than in Panulirus. The individual setae are also differently deve- 
loped. Paribacus lacks the outer blunt clubs, but has in stead long 
blunt spines of large diameter separated by 2 or 3 rows of small 
spines from the outer rim. Again some of the inner setae are very 
markedly serrated or rather set with oblique plates on the outer 
face so that they form combs or rasps. 
The rasp-like form of seta is faintly developed in the like 
position in Panulirus also. Taken altogether the arrangement and 
characters of these cleaning setae may, as in the setae of annelids, 
prove of use in distinguishing species or genera since they may well 
be specific as are so many of the organs in erustacea connected with 
reproduction. 
The setae in the claw of Paribacus are much smaller than those 
in Panulirus and do not form the same dense brushes. Thus Fig. D 
being more magnified than Fig. B still shows the setae smaller. 
The smallness of the setae is especially marked on the surface of 
the thumb, where they are invisible to the naked eye. In the finger 
the setae are few and more scattered and the very largest is near 
the outer edge; in the thumb the setae are more numerous 
