72 Journal of Travel and Natural History 



by the workmen, under directions of J. C. Voorhees, about two miles south 

 of Bamesbro, Gloucester Co., New Jersey. The bones were taken from 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, revealing the carnivorous 

 enemy of the great herbivorous Hadrosaurus, as the Dinodon was related to the 

 Trachodon of the Nebraska beds, and the Megalosaurus to the Iguanodon 

 of the European Wealden and Oolite. In size this creature equalled the 

 Megalosaurus Bucklandii, and with it and the Dinodon constituted the most 

 formidable ty]Des of rapacious terrestrial Vertebrata of which we have any 

 knowledge. In its dentition and huge prehensile claws it resembled closely the 

 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 disproportion between 

 the fore and hind limbs of the Igiianodon, together with the compressed 

 form of the tail, suggested to Professor Owen an aquatic habit, a relation of 

 proportions of limbs to habit seen in the tailless Batrachia. The discovery 

 of the massive short-toed foot of the Iguanodon subsequently has lent little 

 countenance to the supposition of its entire adaptation to aquatic life. Dr 

 Leidy has regarded this disproportion in the case of the Hadrosaurus as an 

 index of a habit like that of the kangaroos (Macropus, &c. ), and that that 

 monster rested in an oblique position on the hind limbs and tail, and reached 

 upwards with its muzzle and short fore-limbs to the foliage on which it fed. 

 That such a habit characterized the Laelaps is very probable ; the tail was 

 nearly cylindric, and from the extent of the condyles of the femur the hind limb 

 must have been considerably flexed. The small size of the fore-limbs must have 

 rendered them far less efficient as weapons than the hind feet in an attack on 

 such a creature as the Hadrosaurus ; hence, perhaps, the latter were preferred in 

 inflicting fatal wounds. The exceedingly eagle-hke character of the digits and 

 claws and ornithic type of sacrum, elucidated by Professor Owen, suggest a re- 

 semblance in the use of the limb. The bulk of the species, as compared with 

 that of Hadrosaums, illustrates again the law observed in the relation between 

 Felis and Bos, Thylacoleo, and the herbivorous unplacentals of its time, and 

 the other raptorial and herbivorous Dinosauria, which might probably he 

 reduced to exact terms. The remains indicate an animal of near i8 feet in 

 length, which could probably raise itself to a height of 6 feet at the rump. 

 The genus (Laelaps) belongs to the family Dinodontidjc, which is characterized 

 by its contractile raptorial claws and slender digits and compressed sabre-shaped 

 teeth. It differs from Megalosaurus in its femur, and from Dinodon in that the 

 teeth of the latter have two posterior serrate edges separated by a posterior 

 plane. From supposed Dinosaurian genera of doubtful affinity it differs, e.g.^ 

 from Regnosaurus (Mant. ) in the totally different humerus, and from Pelorosaurus 

 and Strejitospondylus in the vertebrae. Cetiosaurus and Cimoliasaunis were 

 perhaps mutilate like the Cetaceans, according to Owen and Leidy. — Proceedings 

 of the Academy of Natural Sciences of Piiiladelphia, 1866, p. 279. 



