118 Proceedings of the Royal Society of Victoria. 



cavity of the gizzard for a distance of 4 mm., capped by strong 

 yellow chitin, bearing teeth, and spi'eading laterally at the 

 summit to "3 mm. The depth across the face, at the summit, 

 from the upper to the under border measures -7 ram. The 

 centre at the summit is concave on the upper surface, and under- 

 neath is a thin lip curving somewhat upwards with four or five 

 strong pointed teeth which project a short distance into the 

 cavity of the gizzard (Fig. 4, M.T.). On each side of this branch 

 two very short chitinous extensions, similar to each other, with 

 flat surfaces, having short blunt points scattered over the 

 surface (Figs. 4 and 5, M.T.A.). They are directed laterally 

 with their under or posterior border fringed with four strong 

 pointed teeth projecting outwards and curving upwards. This, 

 as a whole, we may call the median tooth. 



On each side of the lateral extensions of the median tooth are 

 two large paired teeth, which arise from the middle fold, but 

 nearer the radial wall and project further into the cavity of the 

 gizzard (Figs. 4 and 5, L.T.). As each tooth arises from its base 

 it points laterally, but curves round and upwards in a half spiral 

 turn, to point towards the centre ; thus they are more anterior 

 in respect to the opening of the gizzard than the lateral exten- 

 sions of the median tooth, and also more lateral. These lateral 

 teeth have the under surface flat and broad, and clothed with 

 little blunt points (Fig. 5), and this surface faces the flat 

 surface of the appendages of the median tooth to unitedly form 

 an obtuse angle, divided by a small space. The opposite or 

 upper surface (Fig. 4) is rounded and possesses a row of pointed 

 projections directed inwards, and each tooth tapers towards the 

 apex. They are united by a band of chitin. 



Longitudinal muscles follow the fold inwards for some 

 distance. 



Fringing the sides of this median fold, and hanging down 

 somewhat underneath are chitinous membranes clothed with long 

 fine setaj pointing towards the centre, and on each side of these 

 arise from the radial wall two projections, with the appearance 

 of a bluntly -pointed apex when viewed from above, as shown in 

 the section, but they are membraneous, and the wall of each 

 bends over downwards. They are clothed with setai pointing 

 centrally. 



