276 PROCEEDINGS OF THE ACADEMY OP 



phalanges, lumbar sacral and caudal vertebrae, and numerous other elements 

 in a fragmentary condition. 



The animal was found by the workmen under direction of J. C. Voorhees, 

 Superintendent of the West Jersey Marl Company's pits, about two miles 

 south of Barnesboro, Gloucester Co., N. J. 



The bones were taken from about twenty feet below the surface, in the top 

 of the "chocolate" bed, which immediately underlies the green stratum 

 which is of such value as a manure. 



The discovery of this animal filled a hiatus in the Cretaceous Fauna, re- 

 vealing the carnivorous enemy of the great herbivorous Hadrosaurus, as the 

 Dinodon was related to the Trachodon of the Nebraska beds, and the Mega- 

 losaurus to the Iguanodon of the European Wealden and Oolite. 



In size this creature equalled the Megalosaurus bucklandii, and with 

 it and Dinodon, constituted the mo^t formidable type of rapacious terrestrial 

 vertebrata of which we have any knowledge. In its dentition and huge pre- 

 hensile claws it resembled cjosely Megalosaurus, but the femur, resembling 

 in its proximal regions more nearly the Iguanodon, indicated the probable 

 existence of other equally important differences, and its pertinence to another 

 genus. For this and the species the name of Laelaps aquilunguis was 

 proposed. 



The following were some of the special characters. 



Mandible. Two portions, one from the anterior pari of the ramus. The 

 latter measure three inches in depth from the outer alveolar border, which is 

 a little more elevated than the internal, and 1.5 in. in thickness at the frac- 

 tured edge. A longitudinal series of vascular foramina extends along the 

 middle of the external face. The teeth are implanted in deep alveolae, had 

 oval compressed fangs, and lenticular compressed crown, with large pulp 

 cavity. The crown was elongate, subacute and slightly curved backwards, 

 minutely striate, and strongly serrate on both edges to near the fang ; this 

 portion of a young tooth yet in the alveolus measured 2Jin. long and ll-16ths 

 in transverse diameter. 



Left Femur. The great external trochanter massive and elevated to the 

 plane of the head, from which it is only separated by a slight depression, and 

 to which it is slightly transverse. The head not projecting far beyond shaft, 

 and without constriction below. In Megalosaurus the head is produced be- 

 yond a kind of neck, and the great trochanter is much smaller and lower 

 down, differing thus from the other known Dinosaurs. The femur of Lae- 

 laps is therefore much flattened from before backwards above, but is cy- 

 lindrical and curved backwards medially. Distally the condyles are more 

 like Megalosaurus than Hadrosaurus or Iguanodon, yet quite different from 

 the first. The length of the inner condyle greater than the transverse ex- 

 tent of the two, the popliteal groove deeper and the trochlear aspect more 

 concave, leaving a narrower connection between the condyles. The inner 

 condyle was much narrower and both more projecting than in Megalosaurus. 

 The third trochanter is small, and lower down than in any known Dinosaur, 

 being removed less than one-third the length of the femur from the inner 

 distal condyle. 



In. 



Length of femur, 31 



Breadth across head and great trochanter, 6| 



Circumference medially, 11 



Antero-posterior length of inner distal condyle, 6.5 



" " " outer " " 3.25 



Transverse extent of united condyle, 4.5 



" " popliteal groove (at middle) 1.5 



Right tibia. The tibia is more slender than that belonging to Megalosaurus 

 described by Prof. Owen, and the distal articular surface, instead of being 



[A 





