400 UTEICULAEIA NEGLECTA. Chap. XVII. 



bladder, as shown in the longitudinal section (fig. 20) 

 of the collar and yalve ; it is also shown at e, in fig. 18. 

 The edge of the vah^e can thus open only inwards. 

 As both the valve and collar dip into the bladder, a 

 hollow or depression is here formed, at the base of 

 which lies the slit-like orifice. 



The valve is colourless, highly transparent, flexible 

 and elastic. It is convex in a transverse direction, 

 but has been drawn (fig. 19) in a flattened state, by 

 which its apparent breadth is increased. It is formed. 



Fig. 20. 

 ( rtricularia neglecta.) 

 Longitudinal vertical section through the A-entral portion of a bladder; showing valve 

 and collar, v, valve ; the whole projection above c forms the collar; h, bifid pro- 

 cesses ; s, ventral surface of bladder. 



according to Cohn, of two layers of small cells, which 

 are continuous with the two layers of larger cells 

 forming the walls of the bladder, of which it is evi- 

 dently a prolongation. Two pairs of transparent 

 pointed bristles, about as long as the valve itself, 

 arise from near the free posterior margin (fig. 18), 

 and point obliquely outwards in the direction of the 

 antennae. There are also on the surface of the valve 

 numerous glands, as I will call them ; for they have 

 the power of absorption, though I doubt whether 

 they ever secrete. They consist of three kinds, which 



