1873.] HTTLKE — ANATOMY OF HTPSILOPHODON FOXII. 529 



tically to the plane of the ilium. A thin, slender, outer trochanter, 

 separated from the upper end of the shaft by a narrow fissure, 

 strongly recalls the similar process in the thigh-bone of Iguanodon. 

 The shaft has an ontward twist, larger, I think, than in Iguanodon. 

 The femoral condyles are strongly developed, and they project very 

 strongly backwards, separated here by a very deep intercondyloid 

 groove. The anterior intercondyloid groove is worn away in the 

 M antell-Bowerbank femur, and it is effaced by squeezing in my spe- 

 cimen; but I have seen it a well-marked deep groove, differing, 

 however, from the groove in the femur of Iguanodon by the 

 absence of overhang, the lips of the groove in Hypsilophodon not 

 being inclined towards each other, and not forming the tunnel which 

 marks the thigh-bone of the great Dinosaur. The length of my 

 femur cannot now be ascertained ; but those of three others were 

 7, 7, and 542 inches. 



Tibia (jig. 8, a). — I have secured in one block the distal end of the tibia 

 with the pes. The length of this shin-bone cannot be learned ; but 

 that of a beautifully perfect example from another individual was 

 9-25 inches, the femur of the same being 7 inches long. The 

 proximal end of this bone was divided into two condyles, answering 

 to those of the femur, but not so strongly marked as these were ; 

 and beyond the outer condyle a large crest projected forwards and 

 outwards from the front of the upper part of the shaft. The axis 

 of the shaft has a strong twist in the same direction as that of the 

 femur. The distal end is transversely expanded, and it closely 

 repeats that of the Iguanodon. 



The fibula is very imperfectly known to me ; I believe it to be 

 rather shorter than the tibia. 



Pes (fig. 8). — The astragalus is disconnected from the tibia in my 

 specimen ; but in two other examples I have seen it attached to it. 

 Its lower surface is pulley-shaped, convex from back to front, and 

 sinuous transversely, being in this direction convex laterally and 

 hollow mesially. The upper surface is concave from back to front, 

 and in this direction it is subdivided by a ridge which marks off two 

 facets answering to those on the distal articular surface of the tibia. 

 The anterior margin is a very thin lip : in my specimen the ex- 

 treme edge has been broken off; but its thinness is such that it can- 

 not have here been produced into a bird-like ascending process. 

 The posterior border is stouter. 



Under the distal end of the tibia, and partially hidden by it, are 

 two small bones, probably tarsals ; the larger and outer one may be 

 a calcaneum. 



There were certainly four (if not five) toes, of which the outer 

 three are well preserved; their ossicles still maintain, with only 

 slight disturbance, their proper relations. The metatarsals are long 

 and stout ; their proximal ends have been flattened by a hard sand- 

 stone nodule. The middle one (the longest) measures 2-8 inches 

 long ; the outer one is 2 - 3 inches, and that on the inner side of the 

 central one is 2-5 inches long. Displaced, and lying beneath these 

 three, athwart them, I discovered an ungual phalanx, and not far 



