PLATE XXXVI11. 



(The cost of this plate has been defrayed by the Carnegie Trust for the Universities 



of Scotland.) 



Fig. 



1. Holurus Parki, Traquair. Entire specimen, natural size; showing especially the 



head and the dorsal and caudal fins. From the Lower Carboniferous (Calciferous 

 Sandstone Series), Glencartholm, Eskdale. Royal Scottish Museum, Edinburgh. 



2. Another and somewhat larger specimen of the same species, also represented of the 



natural size. From the same horizon and locality. In the Royal Scottish 

 Museum. 



3. One of the type specimens, previously figured by the author in 'Trans. Roy. Soc. 



Edinburgh,' vol. xxx, pi. iii, fig. 9. Natural size. In the Collection of the Geo- 

 logical Survey of Scotland. Same horizon and locality. 



4. Flank-scale, magnified six diameters. 



5. Scale further back, also magnified six diameters. 



6. Median dorsal scales, also magnified six diameters. 



