362 G. J. HINDE ON CAMBRO-SILURIAN 
mentary teeth and six plates have been crushed together in a small 
patch of about one fourth of an inch in diameter, in black shale. 
The specimen was discovered in splitting open a slab of the rock, 
the division taking place in the centre of the specimen. No indica- 
tion can be seen of the natural position of the teeth and plates; but 
it can hardly be doubted that they all belonged to one individual, as 
it would be beyond all reasonable probability thatso many diversely 
formed teeth, of such delicate structure, could have been thus brought 
together into so small aspace by mechanical means, more particularly 
when it is a very rare circumstance to find, in the same rock, even 
two detached teeth at all close together; and in only one other in- 
stance have I found two Conodonts partially connected together, and 
these are forms which are present in this compound example. If, 
however, these various teeth and plates were attached in their natu- 
ral positions by soft tissues merely, by the decay of these they 
would be liable to be crushed together into a shapeless mass like 
that presented by the specimen. 
Potyenatuus pusius, Hinde. (PI. XVI. figs. 6-18.) 
The only example discovered in which the teeth of this remarkable 
form are grouped together has been crushed to such an extent that 
the individual teeth and plates can be only partially distinguished ; 
but the various kinds are met with in a very perfect condition, as 
SO many separate specimens, scattered through the rock. As these 
detached teeth occur not only in the rock in which the grouped 
specimen is found, but are widely distributed even in Lower Carbo- 
niferous rocks, I append descriptions and figures of the individual 
teeth and plates. 
For the convenience of reference I refer the teeth to pectinate, 
fimbriate, and crested forms. 
1. Pectinate teeth —Of these the kind figured in Pl. XVI. figs. 6-9 
has a narrow, slightly arched base and a main tooth which is some- 
times produced below the level of the base ; the secondary teeth are 
slender and acute, and vary from 14 to 20 in number. This kind 
averages about ? line in length, and is abundant in the “ Conodont- 
bed” of the Hamilton group as well as in the Genesee Shale at 
North Evans. 
Another variety of pectinate compound teeth, shown in Pl. XVI. 
figs. 10, 11, 12, has the base straight and almost linear ; there is no 
distinctive central tooth, but a series of similarly shaped teeth, 
sometimes as many as 14, of which the central ones are the longest. 
Occasionally smaller denticles are intercalated. The base of these 
forms is about 2 line in length, and the longest teeth from 3 to 3 line 
long. ‘This variety is very widely distributed. It has been described 
by Pander under the name of Centrodus simplea (‘ Monograph.’ p. 31, 
tab. 24. figs. 2, 3, 5, 6), from the Lower Carboniferous in Russia ; it 
occurs in the same formation at Bedford, Ohio, and also appears in 
Genesee Shale at Kettle Point, Ontario, as well as at North Evans, 
New York. 
2. Iimbriate teeth (Pl. XVI. figs. 13, 14).—The base of these com- 
