WELLBURN : FISH FAUX A OF THE LOWER COAL MEASURES. 425 
denticles, which are placed alternate to those on the posterior 
borders. The posterior border of the spine is nearly straight, 
but the anterior one is gently curved from base to tip. The 
dividing line between the inserted and excerted portions is well 
marked, the line cutting the anterior and posterior margins at 
an angle of 45°. See PI. LXI., fig. 1, n, h. 
Genus : IIoplo7ichus Davis. 
Sp. H. elegans Davis. 
Small spine from the Halifax Hard Bed Coal Shale. It is 
curved and shows the usual ornamentation of smooth, well- 
spaced longitudinal ganoine-coated ridges. Denticles not shown. 
Order : Acanthodil 
Family : Acanthodidse. 
Genus : Acanthodes Agassiz. 
Sp. A. Wardi Egerton. 
Fin spine, scythe-shaped, much laterally compressed, with 
a groove and faint ridge parallel with the anterior margin dis- 
appearing distall}'. Distals flattened. Found in both districts. 
PI. LXI., fig. 2. 
IncertcB sedis. 
Stemmatodus St. John and Worthen, 1875. 
Sp. indet. They are clusters of denticles, and are probably 
dermal appendages of some extinct Shark. According to Prof. 
Anton Fritsch they are "gill rakers" of some shark. 
Sub-class : Teleostomi. 
Order : Crossopterygii. 
Sub-order : Rhipidistia. 
Family A.: Rhizodontidse. 
Genus I. : Strepsodus. 
Sp. S. sauroides Binney. 
Teeth show^ing the usual character, viz., laterally compressed 
and plicate at the base, but above this point the transverse 
section is nearly circular, relatively long and slender, apex 
sigmoidally bent, inner surface covered with well-spaced prominent 
fine striae, external surface smooth. PI. LXI., fig. 5. 
