PLATE 100. 
Page 
Fig. 1 & 2. Avicula textilis, var. arenaria. 465 
1. An impression made in sandstone by the exterior surface of the smaller or right valve. 
2. The imprint of the exterior of the left valve of this species. 
Fig. 8. 
Avicula recticosta. 
466 
Fig. 4. 
4. 
Megambonia bellistriata. 
A cast of the left valve, from a mould of the exterior in sandstone 
467 
Fig. 5 & 6. Megambonia lamellosa. 467 
5. The left valve of a specimen of this species. 
6. The left valve, showing a proportionally more extended wing than the preceding. 
