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e. Abdomen. Testis region. 6 segments. 
/. Abdomen. Caecum region. 6 segments probably. 
g. Anal region. 
h. Posterior sucker. 
Fig. 1. Platybdella anarrhichae. The entire animal viewed from the ventral surface. 
An unstained balsam-mounted specimen. Lettering as explained in the text. 
m.g. male genital aperture; f.g. female genital aperture; t 1 , l T> the first and last 
apparent pairs of testes. 
Nervous System. The ventral nerve cord resembles that of other 
Ichthyobdellid leeches, and lies within the ventral sinus. 
Coelom. The body cavity is divided into the five following parts: 
a ventral sinus (containing a blood vessel), a dorsal sinus (containing 
Parasitology vm 18 
