NATURAL SCIENCES OF PHILADELPHIA. 277 



lozenge-shaped, is cuneiform, the inner wide extremity oval rounded. In- 

 ner transverse breadth of proximal head one-fourth total length. Anterior 

 ridge very strong, much incurved, disappearing at between the proximal 

 fifth and fourth of length ; internal ridge on proximal half, strong, but not 

 reaching condyles. Posterior condyles separated by a deep notch, inner 

 larger than outer ; (outer larger, Megalosaurus bucklandii). Shaft much 

 compressed from before backwards, and distal articulation at right angles to 

 proximal, concave on its interior half. 



In. 



Length of -tibia, , 30.75 



Circumference proximal head, 15. 



Antero-posterior diameter do 7.5 



Posterior transverse do. do .... 5.5 



Transverse length distal condyle, , 7. 



Longitudinal inner breadth, 2.5 



Circumference o shaft at middle, 10.5 



These long bones are hollow, with thick walls of dense bone ; diameter of 

 medullary cavity at middle of tibia 1.5 inch. 



Fibula. Twenty-three inches preserved, proximally concave and dilated ; 

 condyle curved, narrow acuminate oval, in profile concave, then rounded 

 descending; length 6 in., median breadth 1.75 in. Just below the condyle 

 on the inside is a deep concavity with abrupt superior and lateral walls. Shaft 

 less flattened below, but slender, reaching a width of 1^- in. 



Humerus. Both are preserved, but lack the distal condyle ; about half the 

 olecranar fossa of one remains, furnishing an indication of the breadth of that 

 extremity. They are proximally much dilated, having a very strong postero- 

 external ala and a shorter antero-internal dilatation. They are not half the 

 length of the femur ; the shaft is flattened antero-interually. Of the proxi- 

 mal articulating surface the proper condyle is lost, but a narrow surface 

 continuous with it externally does not extend further out on the dilation than 

 opposite to the middle of the shaft. Olecranar fossa large and well marked, 

 not near to penetrating ; medullary cavity of shaft relatively smaller than in 

 the bones of the leg. 



In. 



Length of humerus (restored), 12 



Greatest proximal breadth, 3-75 



Distal breadth across olecranar fossa, ., 3. 



Circumference of shaft, '. 5.^ 



These humeri are relatively shorter than in Hadrosaurus and Iguanodon, 

 and the external alae do not pass so abruptly into the shaft as in them. 



? Clavicles. Two lateral elements are nearly similar to those identified by 

 ' Owen in Iguanodon with clavicles, and by Leidy in Hadrosaurus with the 

 pubes. Their disproportionate size, as compared with the humeri in Lae- 

 laps, renders their recognition as clavicles difficult ; they are very unlike 

 usual forms of pubes. Each has a gentle sigmoid flexure, and a subtrigonal 

 section They are flattened at the inner extremity and dilated with a margin 

 at right angles to the shaft; the whole extremity is not preserved; the flat- 

 tened portion is hollow, while the shaft is entirely solid. Length 18.5 inches. 

 Phalanges. No. 1. An ungueal phalange of remarkable size and destruc- 

 tive use. The depth at the proximal articulation is about the same as in 

 Megalosaurus bucklandii, (two inches without inferior tuberosity) but 

 the length is considerably greater. Form everywhere compressed, especially 

 at tip, rounded above. Below the articulating surfaces is the point of in- 

 sertion of a large flexor tendon, a flattened subglobular process, separated 

 by a groove except in front. The groove extends on each side distally on 

 the middle, to the tip. The general form is not unlike that of a rapacious 

 bird, but is more compressed. 



1866.] 



