CARBONIFEROUS CONODONTS OF WEST OF SCOTLAND. 343 



Polygnathus scitulus, Hinde, new species. Plate IX., Figs. 9, 

 10, 11. — Tooth somewhat triangular, with a slightly curved 

 basal margin with a sub-central well-developed cup-shaped cavity. 

 At one extremity of the tooth is a large, compressed, triangular 

 denticle with an acute outer edge ; behind this is a series of 7 to 

 14 minute elongate denticles, closely disposed side by side. 

 [In Scotland it occurs at Linn Spout, Monkcastle, Glencart, 

 Hillhead, Orchard, and Limekilns. Specimens measure 8 mm. 

 in length.] 



Prioniodus Tulensis, Pander, Mon., p. 30, t. 2a, f. 18, 19, 20. — 

 A relatively large curved tooth, with one or more horizontal or 

 oblique divergent processes at its base, on which there are 

 occasional and smaller denticles. These appear to be similar 

 to Pander's specimens, which were from the lowest beds of 

 the Carboniferous limestone in the province of Tula, Russia. [In 

 Scotland it occurs at Glencart, Law, Glenbuck, and Skate- 

 raw, near Dunbar. Plate IX., Figs. 15, 16, 17. Specimens 

 measure from I'O to 1'6 mm. in length.] 



Prioniodus angulatus, Hinde. Quar. Jour. Gtol. Soc, 1879, p. 



360, pi. 15, f. 17. — Tooth with an angular flattened base, with a 

 prominent compressed denticle at the apex and several smaller 

 on either side. It is present in the Devonian of New York and 

 the Carboniferous of Ohio. [In Scotland it occurs at Glencart, 

 Monkcastle, and Birkhead. Plate X., Figs. 18, 19. Specimens 

 measure from 1*0 to 1*1 mm. long.] 



Prioniodus spicatus, Hinde. Quar. Jour. Geol. Soc, 1879, p. 



361, pi. 16, f. 1-3. — Tooth with a narrow horizontal base, carrying 

 a few minute denticles and a single large, curved, terminal 

 denticle which is extended below into a small spiked process. 

 It occurs in the Devonian of North America. [In Scotland it is 

 got at Birkhead. Plate X., Fig. 20. Only one specimen has been 

 found, '5 mm. in length.] 



Prioniodus per acutus, Hinde, new species. Plate X., Figs. 21, 

 22, 23. — A single straight or slightly curved, compressed main 

 tooth which extends below a small horizontal base to an obtuse 

 point, the outer margin, and both margins below the horizontal 

 process, are acute. There are a few minute, closely set denticles 

 on the horizontal base. This form differs from P. sjncatus in its 

 larger size, the sharp edges of the main tooth, and in the very 



