PLATE XXIV. 



Fig. 



1. Plaster mould from an impression of the outer surface of an anterior median 



dorsal plate of Both riolepis major from Alves, in the Elgin Museum. One 

 half natural size. 



2. Internal surface of a similar but slightly larger plate, with the bony substance 



preserved, belonging to the Royal Scottish Museum. One half natural size. 



3. Plaster mould from an impression of the outer surface of a left dorso-lateral 



plate from Rocky Park, Alves, belonging to the Royal Scottish Museum. 

 Lateral line groove well shown. One half natural size. 



-i. Plaster mould from the counterpart of the same specimen, also in the Royal 

 Scottish Museum. Here the internal surface of the plate is represented, 

 and shows conspicuously the extensive surface behind for overlapping the 

 posterior dorso-lateral plate. 



5. Plaster mould from an impression of a median ventral plate, from Alves, near 

 Elgin. One half natural size. 



