PLATE: A 
Fo Ay POTS 
Fig. 1. Thompsonia on Synalpheus brucei. Young external sacs on the abdominal and thoracic 
appendages. x 3 
Fig. 2. The same at a later stage. The external sacs now contain Cypris larvae which are roughly 
indicated within. x 3. 
Fig. 3. Thompsonia on Thalamita prymna. To show the very large number of external sacs occurring 
on this specimen. Natural size. 
Fig. 4. Thompsonia on Acteea ruppellii. External sacs pear-shaped. x 2. 
The first three specimens figured are from Murray Island, the fourth from South Africa. 
