150 
Sir EveRard Home on the double organs of 
cc. The same, magnified fifty times. 
Fig. 6 . The tail portion of a worm opened from behind ; 
magnified four times. 
To show that the ova and membranous bags are not met 
with at the lowest part of the worm, the compartments con- 
taining clusters of agglutinated ova, embryos, and crysales. 
Fig. 7. One of the clusters of the last figure ; magnified 
thirty times. 
Fig. 8. The same cluster kept in water for fifteen minutes, 
and its contents exposed. 
Fig. 9. Two perfect crysales from the same cluster ; mag- 
nified fifty times. 
Plate XX. Barnacles. 
Fig. 1. A portion of the pedicle, with the shell from which 
the left valve is removed. 
Fig. 2. A Longitudinal section of Fig. 1, to show the eggs 
within the fibrous substance of the pedicle ; and the animal 
removed, to show the mantle in its natural position lining 
the shell ; natural size. 
Fig. 3. The entire animal taken out of the shell, and the 
mantle or lining of the shell turned back ; magnified two 
diameters. 
Fig. 4. The animal with the external membrane turned 
back, to show the eggs which accumulate there before they 
pass into the pedicle ; magnified two diameters. In these 
two figures the tentacula of the right side are removed, to 
prevent confusion. 
Fig. 5. The animal with all its integuments removed, and 
also the tentacula of the left side removed to show the natural 
position of the penis ; magnified two diameters. 
