PLATE I. 



The following letters have the same signification throughout, 



d, Cloacal papilla or opening. 



i. Intestine. 



'/«. Mouth. 



p. Parapodium. 



ph. Pharynx. 

 s. Sucker. 

 (5 . Male genital papilla or opening. 



Figs. 1-3. Myzostoma membranaceum, n. sp. 

 Figs. 1, 2. The animal, from the ventral side ; magnified 5^ diameters. 

 Fig. 3. The same, from the dorsal side. 



Fig. 4. Myzostoma longicirrum, n. sp. 



Fig. 4. Seen from the ventral side; magnified 108 diameters; Nos. I-X, the 

 number of the cirri. 



Figs. 5, 6. Myzostoma Jissum, Grafi". 



Figs. 5, 6. Seen from the ventral side ; magnified 5^ diameters ; Nos. I-III, the three 

 pairs of caudal appendages. 



