394 THE ALIMENTARY CANAL OF THE IMAGO. 
The fork at the extremity of a ring bounds the edges of the 
scale (Fig. 50), and the single extremity of the ring runs through 
the middle of the opposite scale. 
Anthony's Suckers.—(PI. XXIII., Fig. 2) The figure is taken 
from a very beautiful photograph which Dr. H. M. Wright, of 
Sydney, N. S. Wales, has kindly sent me; it was taken by 
him with one of Powell and Lealand’s latest apochromatic 
objectives. 
The oval spaces between the teeth of the rings have the 
Fic. 50.—Details of the Pseudo-trachez. 7, a section of the oral surface of the 
labelice, transverse to the pseudo-tracheal channels; 2, a surface view showing 
Anthony’s suckers ; 7 and 4, pseudo-tracheal rings showing the position of the 
sacculus forming Anthony’s sucker. @, simple, and 4, forked end of the rings ; 
ct, tendinous cord; d, duct of labial gland; 4, hypoderm ; /, papilla; 7, 
pseudo-trachea ; s, sacculus forming Anthony’s sucker ; ¢7, tracheal vessels of 
disc, 
DESCRIPTION OF PLATE XXIII. 
Two surface views of a portion of the oral sucker, showing the details of the Pseudo- 
trachee and Anthony's suckers, from photographs taken by Dr. H. M. Wright, of 
Sydney, N.S.W., by whose kind permission they are published for the first time. 
Fic. 1.—A portion of the oral surface of the disc, showing the pseudo-trachea and 
orifices of the duct of the labial gland. 
Fic. 2.—A more highly magnified view of a portion of the same, showing Anthony’s 
suckers and the orifice of two of the labial ducts. Taken with an apochromatic y'y. 
(Powell and Lealand.) 
