516 GHOFFREY SMITH. 
completely disappeared and there are no gills attached to the 
limb. 
In the male the openings of the vasa deferentia are situated 
on the inner edges of the coxopodites of the eighth thoracic 
appendage (text-fig. 26). 
In the females of the three living genera a very conspicuous 
spermatheca is to be seen, placed between the last pair of 
thoracic limbs in the ventral middle line (text-fig. 27). It 
consists of a large conical papilla with a single median opening 
THxT-FIG. 24. 
Paranaspides lacustris. Seventh thoracic limb of female. 
which leads into a wide tube. The tube bifurcates into two 
slightly ramifying passages in which spermatozoa may fre- 
quently be found. The tube and its passages are lined with 
chitin secreted by a definite epithelium, and round the 
ramifying bifurcations a cellular tissue is aggregated of a 
connective or supporting character, probably with much the 
same function as cartilage. ‘his tissue is also found in the 
labrum, and its peculiar histological character is shown on 
Pl tee lit 
