— Plate J4. — 



Fig. I.- Ulricularia monanlhos, trap, studded with glands. 



Fig. 2. — Entrance of same, sagittal section. 



Fig. 3. — Same, in diagram to show set {di), relaxed (^2) and quite open 

 {dz) posture of the door. Arrows indicate water pressure on the door; 

 nip, middle piece, the arrow 4 indicating the direction of the thrust of 

 the lateral hinges on it; pmp, arrow indicates the direct thrust of 

 middle piece itself; ov, iv, outer and inner velum; pe, pavement; uh, 

 upper hinge; 2, inner angle of the threshold, th; j, line of attach- 

 ment of door to wall. 



Fig. 4. — Section of trap so made as to allow one to look down through 

 the door (regarded as transparent) so as to see the opening guarded 

 by the outer velum. The two groups of glands on the door's outer 

 surface are shown. The abrupt bend in the threshold is indicated by 

 the transverse, curved dotted line. The other two dotted lines indicate 

 the limits of the lateral hinge. Lettering as in previous figure. 



Fig. 5. — Section across the entrance showing the deeply curved concave 

 threshold (th) and the door fitting into it, held by the thrust of the 

 lateral hinges (long arrow) on the middle piece {mp, short arrow). 

 The dotted lines indicate flexures of the door edge on opening. 



Fig. 6. — The various kinds of traps of U. volubilis. A, short stalked, basal 

 trap; B, long stalked trap, with foliaceous stalk; C, rostrum of A; 

 D, E, dorsal and lateral views of stolon trap. 



Fig. 7. — Variants of the trap of U. Hooker i. A, large trap with deeply 

 laciniate wings; B, its rostrum and wings seen from above; C, 

 medium sized trap with broader wings; D, small trap with ventral 

 wings suppressed, the dorsal wings and rostrum very slender. 



