Plate 1. 



Parasites and hosts. 



All figures natural size. 



Fig. 1. Low male of Inackus seorpio. Vential view. 



Fig. 2. Female of Inackus seorpio. Ventral view. 



Fig. 3. Male of Inackus seorpio with a Sacculina neglecta on it. The abdomen and chelae of the host are 



intermediate in character between those of an ordinary male and female. Ventral view. 

 Fi°\ 4. Male of Inachus seorpio, carrying on its abdomen two specimens of Danalia curvata, and a small 



Sacculina neglecta (dark yellow). Ventral view. 

 Fig. 5. Male of Paclnjgrapsus marmoratus with Sacculina benedeni. The abdomen of host is intermediate 



between male and female in its dimensions. Ventral view. 

 Fig. 6. Female of Eriphia spinifrons with Sacculina eriphiae. The Sacculina assumes a purplish tinge owing 



to the brood of laTvae being ready to hatch out. Ventral view. 

 Fig. 7. Callianassa subterranea with Partlienopca subterranea on its abdomen. The furrow shown on the 



parasite indicates the position of the mesentery. Viewed from left side. 

 Fig. 8. Eupagwus prideauxii with Peltogaster curvatus. The green colouring of the crab's abdomen is due 



to the roots of the parasite shining through. From left side. 

 Fig. 9. Eupagwus meticulosus with specimens of Peltogaster socialis on its abdomen. From left side. 



