ON THE ANASPIDACEA, LIVING AND FOSSIL. 515 
podite, a process which can be observed to occur in some of 
the posterior limbs of Anaspides. If this is so, it is clear 
that the exopodite no longer springs from the basipodite, as 
it normally should do, but from the fused basipodite and 
propodite. 
The second to the sixth thoracic limbs may be treated 
together, as they only differ in unimportant detaiis. As a 
TExT-FIGc. 21. 
Koonunga cursor. Second thoracic limb. ex. Exopodite. en. 
Endopodite. ep. Gills. 
type we may describe the fourth thoracic limb of Paranas- 
pides (text-fig. 22). This limb is composed of a pediform 
endopodite and a flagellate exopodite borne on a two-jointed 
base. The coxopodite bears a pair of gills. We see in 
this limb the process of fusion of the basipodite with the 
propodite, the joint between them being represented by a 
groove which does not completely traverse the fused seg- 
ments. In the more anterior limbs and especially in young 
specimens of both Anaspides and Paranaspides the 
