Bull. U. S. F C. 1899. (To face page 304.) 
Plate 39 . 
Pixloinum areolaturn (?) from Morone americana. 
(10. Ventral view, x 70. 
01. Dorsal view of anterior portion, life; spines not shown except in 
front, x 170. 
I, Opening of Laurer’s canal. 
02 . Spines and opening of Laurer’s canal, life. 440. 
03. Ventrai view, life; spines not shown, x 100. 
Distomum dentatum xp. nor. from Paralichthys dentatus. 
64. Ventral view, life: sketch made after the specimen had been 
lying under the cover glass for some time, x 100. 
0 '>. Dorsal view of oral spines, x 400. 
00. Ventral view of oral spines, x 400. 
07. Flat scale-like spines of body, x 440. 
Distomum fragile sp. uov.from Mala nn la. 
08. Lateral view, alcoholic, x 20. 
69. Ventral view, sketch of specimen in oil of thyme. 70. 
70. Ventral view of anterior end. x 100. 
Distomum xp.from Prionotux enrol i mix. 
71. Outlines of two specimens, life. about 50. 
Distomum xp.from Stenotomus chrysops. 
72. Ventral view, life, spines not shown, x 68. 
a', Spherical bodies with concentric structure. 
