4 BRITISH FOSSILS. 



straight serrate edge furnished with fourteen teeth, besides a pro- 

 minence on the very small hasal lobe. The uppermost tooth is 

 minute, the second largest of all, but not greatly larger than the 

 rest ; all are short-conical, tolerably equal in size, and a little curved 

 as well as set obliquely, pointing backwards. 



The remaining joints, figs. 7, 8, 9, are well exhibited in three or 

 four specimens, of which fig. 7 shows the impression of the upper 

 side (see for comparison Plate VI. fig. 1.) Figs. 8, 9, are impressions 

 of the lower surface (see fig. 2 of the same plate). 



Basignathite. The second joint b is very narrow, almost linear, 

 and fully three times as wide as long ; the third (or ischygnathite) is 

 linear (?) on the under surface (fig. 8 i) but greatly produced forwards 

 on the upper (fig. 7), so as to touch, by its projecting boss, the fifth 

 joint. The general form is rudely trigonal, or rather trapezoidal, 

 the upper straight edge being only about half the breadth of the 

 lower, which is sigmoid, and near the boss tumid. 



The fourth joint (merognathite) is spherical- triangular before and 

 behind, but on the lower side (fig. 8) it is produced into a long 

 straight process which fits the inner angle of the bend of the limb ; 

 a deep notch on the forward edge receives the condyle of the fifth 

 joint. The outer or front margin is very convex, almost gibbous, 

 and forms the prominent forward angle of the foot, which is more 

 strongly bent than in any other species. 



The fifth joint (carpognathite) is narrow-linear on the upper side, 

 but much broader beneath, about seven lines long by ten or eleven 

 "broad, with a rounded boss anteriorly about midway along the joint, 

 and a deep sinus at the hinder edge to admit the great process from 

 the 



Sixth joint (prognathite). This is broad-linear, or oblong, (the 

 sides straight and parallel) not quite twice as long as broad, exclu- 

 sive of the lobes above and below. 'The upper lobe is rounded, 

 fitting into the posterior concavity on the margin of the preceding 

 joint, the lower lobes are unequal, the hindermost being largest and 

 most pointed, the forward one rounded and shorter, the notch deep, 

 rather wide and straight edged at the point of attachment of the 

 last joint (d). 



(d.) (Dactylognathite.') This is two and a half times as wide as long, 

 contracted at the base, widest above its middle part, and ending in 

 a blunt point. The margin of this and the preceding joint are 

 minutely serrate. 



Locality. Lesmahago, an abundant species. Collected by Mr. K. 

 Slimon. The specimens are all in the Museum of Practical Geology. 



