24 FOSSIL REPTILIA OF THE 



A dermo-neural bone overlies the ninth and tenth caudals (Tab. VIII, firr. i) ; 

 another over the seventh and eighth (d n) ; a third over the sixth and fifth. The 

 fracture through the middle of this latter bone (Tab. VII, fig. 3), shows the form 

 and depth of the angular excavation at its base, which rested, probably with inter- 

 posed ligamentous substance, upon the summit of the neural spine of the caudal. 

 The corresponding dermo-hsemal bones, displaced so as obliquely to overlap the 

 haemal spines on the right side, are also preserved ; and on this side there are as 

 many dermo-lateral scutes, but more fragmentary and dislocated. 



In the block of lias with the first five caudal vertebrae (Tab. VII, figs. 1 and 2), 

 is the anterior half of the dermo-neural overlapping the fifth and sixth of that series. 

 Two similar bones with a basal excavation exposed by fracture in one of them, are 

 situated to the right side of the fourth and third caudals, which may be dermo- 

 laterals or displaced dermo-neurals. A portion of a massive dermal bone lies upon 

 a part of the ilium contained in this slab. The rest of the armour of this part of 

 the base of the tail has been removed. The like is the case with regard to the 

 upper part of the block including the sacrum (Tab. VI). At its under part, in 

 which are imbedded dislocated bones of the hind limbs, there are a few scattered 

 portions of wedge-shaped dermal bones, similar in size to those at the base of the 

 tail, but less pyramidal, and with more obtuse summits. A few smaller, flatter, 

 subcircular dermal bones were met with in the course of exposing the parts of 

 the endo-skeleton. One of these (ib., d), lies above the interspace between the left 

 ilium and the third sacral rib (Tab. VI, fig. 1, d). 



In the block of lias containing the fore part of the thorax and scapular arch a 

 longitudinal series of eight dermal bones were found on the right side, overlapping 

 the ribs, external to the diapophyses. These dermal bones were shorter and thicker 

 than the caudal dermo-neurals, and had been subject to more or less fracture and some 

 displacement. The best preserved was wedge-shaped, with the sides of the exca- 

 vated base slightly convex, 2 inches in length, 8 inches 9 lines in breadth, the sides 

 converging at a more open angle, but unequally, to a margin which shows a 

 convex ridge. The inferior size and unsymmetrical shape of this bone seem to 

 show that it formed part of a lateral row, which had been situated near a middle 

 one, or had ranged along near the medial line of the back. The margins of these 

 bones were not entire. The summit of a dermo-neural spine remains wedged 

 between the spines of the second and third dorsals, and another between those 

 of the fourth and fifth dorsals (Tab. II, dn, dn). On the left side of the thorax 

 (Tab. Ill), are preserved some of the upper lateral series of dermal bones {dn i), 

 showing their natural position and intervals. On the same side, beneath the 

 foregoing (Tab. Ill, d i) are some larger wedge-shaped dermal bones. Three 

 of these may have been displaced from above the neural spines. They are 

 elliptical; 3 inches long, 2 inches broad at the base, with the sides converging 



