344 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



short horizontal base. [Occurs at Glencart, Robroyston, Monk- 

 castle, Stacklawhill, Limekilns, Low Baidland, and Law. 

 Specimens measure from '8 to 1*5 mm. in length.] 



Prioniodus complex, Hinde, new species. Plate X., Fig. 24. 

 — Tooth with a slightly compressed sinuous base. At one end the 

 primary denticle projects to form a spike-like process beneath the 

 base ; next to this is a large, upright denticle which is succeeded 

 by a series of about 1 6 minute denticles. At the end of the base 

 is another large denticle, obliquely projecting forwards, the front 

 margin of which is minutely serrated. [Occurs at Linn Spout 

 and Glencart. The largest specimen measures 1'4 mm. in 

 length.] 



Prioniodus geminus, Hinde, new species. Plate X., Fig. 25. — 

 Basal portion consisting of two straight or slightly curved arms, 

 carrying minute denticles often unequal in size ; the arms meet 

 at an acute angle, and at the apex is a large, compressed, double- 

 edged denticle. [Occurs at Glencart and Linn Spout. A 

 complete specimen measures '7 mm.] 



Prioniodus porcatus, Hinde, new species. Plate X., Fig. 26. — 

 Tooth with a short, narrow, somewhat compressed base, which 

 carries five or six minute, conical, obliquely placed denticles, and 

 is terminated by a slightly curved, conical, acutely pointed larger 

 denticle, which projects obliquely forwards. [Occurs at Monk- 

 castle. Only one specimen found; 1*1 mm. in length.] 



Ctenognathus obliquus, Pander. Mon., p. 35, pi. 2a, f. 11. — 

 The basal portion of the tooth is horizontal and compressed ; at 

 or near one extremity is a large conical, acutely pointed denticle 

 at right angles or oblique to the base, with a series of minute 

 sharply pointed denticles on one or both sides of it. [Occurs at 

 Birkhead and Law. Plate X., Figs. 27, 28, 29. A complete 

 specimen measures 1*4 mm. long.] 



EXPLANATION OF PLATE. 



Figure 1. — Polygnathus dubius, Hinde, x24; from Lower Limestone, 



Birkhead, Dairy. 



Figure 2. — Polygnathus (Gnathodus) Mosquensis, Pander, x22 (side 



view); from Upper Limestone, Monkcastle, Kilwinning. 



