
CARBONIFEROUS CONODONTS OF WEST OF SCOTLAND. 341 
Cunningham Baidland, Dalry. 
Birkhead, Dalry. 
Law, Dalry. 
Low Baidland, Dalry. Lower 
Auchenskeith, Dalry. Tameneaare. 
Ponniel Water, near Douglas. 
Glenbuck, near Muirkirk. J.8.] 
DESCRIPTIONS OF THE CONODONTS. 
Polygnathus dubius, Hinde, l.c., p. 362, pl. 16, £. 6-18.— 
Numerous small teeth and plates are associated together in this 
species, and some of the same form are present also in the Ayr- 
shire deposits. The first of these has the basal portion flattened, 
and its lower margin slightly curved; near the centre of the 
base there is a compressed triangular large denticle, with from 4 
to 10 similarly shaped smaller denticles on either side of it. 
I have found this form in the Devonian of America, l.c., pl. 16, 
f. 8; it also occurs in the Carboniferous of Ohio, /.c., pl. 57, f. 1, 
2, 13; and of Russia, l.c., pl. 2a, f. 16. 
[In the West of Scotland it occurs at Stacklawhill, Robroyston, 
and Birkhead. Plate IX., Fig. 1. Length, 1-3 mm. ; rare.] 
Centrodus duplicatus, Pander, l.c., pl. 24, f. 7.—Tooth with 
narrow, straight, elongated base, from which spring at right angles, 
or occasionally obliquely, prominent pointed denticles, and be- 
tween which are smaller ones. It is present in the Devonian lime- 
stone of Canada, ic., pl. 16, f. 12, and the Carboniferous lime- 
stone of Tula, in Russia. [In Scotland it occurs at Monkcastle, 
Glencart, Birkhead, and Law. Plate IX., Fig. 12. Length of a 
broken specimen, 1‘0 mm. ; rare.] 
Centrodus lineatus, Pander, l.c., pl. 2A, £. 9.—The basal portion 
of this tooth is narrow, elongated, straight or curved, with 
numerous denticles arranged in a single series. Generally the 
denticles are unequal, every third or fourth being more pro- 
minent, and in perfect specimens a longer denticle is present near 
one extremity of the tooth. I have figured this from the Devonian 
of Canada, U.c., pl. 16, £. 13; and it is also present in the Car- 
boniferous of Ohio, Z.c., pl. 57,f£.4, 8; and of Russia. [In Scot- 
land it occurs at Linn Spout, Glencart, Monkcastle, and Orchard. 
