PLATE 1 



EXPLANATION OF FIGURES 



1 Ventral view of the intestine of Corydalis, showing tracheal connections; 

 1th, first thoracic spiracle; ?th, second thoracic spiracle; lab, 2ah, Sab, ^ab, abdomi- 

 nal gills; k, gizzard; n, nerve. The remaining letters are fully explained in the 

 text. 



2 A more enlarged view of the tracheal supply of a portion of the intestine. 

 Letters fully explained in text. 



3 A view of the muscular system of the fore-gut, showing the wonderful net- 

 like arrangement. 



4 The gizzard spread open; s.r., small ridges; l.r., large ridges. The posterior 

 end of the gizzard is at the upper part of the photograph. 



5 One of the large ridges of the gizzard in lateral view, a.t., anterior tooth; 

 p.t., posterior tooth. 



6 One of the large ridges of the gizzard in side view. There are three of the 

 ridges as shown in figure 5, three as in figure 6, and six small ridges as shown in 

 figure 7 in each gizzard. 



7 One of the small ridges of the gizzard. 



8 Cross-section of the oesophagus, showing the numerous folds. 



9 Cross-section of the fore-gut near the middle of the gizzard. 



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