640 BRITISH PALAZOZOIC FOSSILS. [Pisczs. 
Pa@&ciLopus OBLIQUUS (Ag. name only). PI. 3. I. fig. 5. 
Desc.—Terminal posterior tooth sub-cylindrical, obliquely attenuated semielliptically at the posterior end, 
abruptly truncated at an angle of 80° in front, strongly convoluted with three very strongly marked, very 
prominent, nearly equidistant ridges, the lateral ones formed by the thickened reflected margins of the anterior 
and posterior edges; the middle one thicker than the others, and slightly more prominent, bounded on each 
side by a very broad, deep concavity ; the concavities are crossed by strong, subequal, slightly irregular longi- 
tudinal wrinkles, separated by deep sulci (four in two lines), which only indent the oblique transverse ridges of 
the convoluted outer portion: whole surface strongly granulo-punctate. Average length six and half lines, 
greatest width four lines. 
This beautifully distinct species is easily distinguished by the strength and obliquity of the three ridges 
found in Cochliodus. The punctation is rather finer than in the Psammodus cornutus, and in places, is entirely 
concealed by superficial patches of ganoine, such as I have drawn attention to in the Psammodonts generally. 
Position and Locality.—Rare in the lower carboniferous limestone of Armagh. 
Explanation of Figures.—PI. 3. I. fig. 5, left posterior tooth, natural size; fig. 5a, portion of surface 
magnified. 
PcCILODUS PARALLELUS (Ag. name only). PI. 3. I. fig. 6. 
Desc.—Middle tooth only known, narrow, very much inrolled spirally, the curve exceeding a semicircle; 
anterior and posterior margins forming narrow rounded ridges, sharply defined by narrow impressed sulci, and 
converging towards the much inrolled external apex; the posterior margin longer and more oblique than the 
anterior; middle ridge about three times the width of the lateral ones; abruptly raised above their level, so as 
to be very much more prominent, though only moderately convex; middle lobe crossed about its middle or 
most prominent part of the general convexity of the tooth, by about five or six narrow, deep, longitudinal sulci, 
which also, though less strongly, indent the lateral ridges, to which they are nearly at right angles; leaving 
intermediate ridges about half a line wide, not raised above the general level of the surface. Average width 
from base to opposite point of the outer margin (not to the inrolled apex) seven lines, greatest length of base five 
lines; length of middle lobe at same point three and half lines; length of the three lobes together at opposite 
points of the exterior, two lines; punctation of the surface very coarse. 
The teeth which have received this name are remarkable for the excessive incurvation of their external 
apices, as represented in our figure, as well as the patch on the uppermost part of the surface of the longi- 
tudinal inconspicuous ridging. From the character of this ridging, and from the parts on the inner and outer 
sides of it, and the general agreement of the margins, &ec., I have little doubt that this will ultimately prove 
to be the middle tooth of the P. sublevis. Iam not however in a position to absolutely demonstrate the truth 
of my conviction. In the transverse fractures the vertical medullary canals are found to be excessively coarse. 
Position and Locality—Rare in the lower carboniferous limestone of Armagh. 
Explanation of Figures.—P). 3. 1. fig. 6, front view of penultimate tooth natural size; fig 6a, ditto, 
shewing the spiral inrollment of the crown for the armature of the exterior of the jaw. 
PacILoDUS SUBL@VIS (Ag. name only). Pl. 3. L. figs. 7, 8, 9. 
Desc.—Posterior tooth aliform, very oblique; articular margin forming an angle of 40° with the straight 
inner edge; tumid anterior margin defined, very narrow; sigmoidal middle ridge close behind it, broadly 
rounded, occupying half the length of the tooth, and forming its most convex part, narrowing gradually to the 
convoluted, beak-like, prominent, outer end ; behind the middle ridge the surface slopes with moderate concavity, 
to the small flattened, acutely angular, posterior end, the outer margin of which is slightly tumid. Surface 
coarsely granulo-punctate, the middle third crossed longitudinally by five or six obscure, sigmoidal, sulci and 
intervening ridges, about three-fourths of a line wide, which are not more elevated than the general surface. 
Length along the inner edge ten lines; greatest width seven lines ; anterior tooth having the posterior margin 
