a 
64 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
EXPLANATION OF PLATES. 
All figures were drawn with the aid of Abbé’s camera lucida, unless otherwise 
stated in the explanation of figures. 
Arabic numerals in the figures designate rings, which, except in the case of Fig- 
ures 23 and 27, Plate 6, are numbered from the extreme anterior end of the body 
backward; Roman numerals designate somites numbered in the same manner. 
ABBREVIATIONS. 
act. Acetabulum (posterior sucker). oc. 
an. Anus. @. 
cb. Brain. or. 
dt. ej. Ejaculatory duct. po. & 
ga. Stomach. po. 2 
gl. d. Dorsal gland. pr. 
gl. sal. Salivary glands. sac. phy. 
in. Intestine. suc. or. 
Vglv. Crop. te. 
lac. marg. Marginal lacuna. va. df. 
nph’po. Nephropore. va. ef. 
oa. Ovary. vs. Sem. 
Eye. 
(Esophagus. 
Mouth. 
Male genital pore. 
Female genital pore. 
Proboscis. 
Pharyngeal sac. 
Oral sucker. 
Testis. 
Vas deferens. 
Vas efferens. 
Seminal vesicle. 
