100 THE EXTINCT BATRACHIA, REPTILIA The fibula in latter stages withdraws from this connection, and becomes much shortened and reduced.* The genera which belong to this order are, Laelaps, Cope ; Poecilopleurum, Deslongchamps ; Megalosaurus, Buckland ; Coelosaurus, Leidy; and perhaps, Bathygnathus, Leidy ; Aublysodon, Leidy. LAELAPS, Cope. Proc. Acad. Nat. Sciences, 1806, p. 275; 1. c.. p. 316; 1. c. 1867, p. 284. American Naturalist, 1867, 27. Dinodon, Leidy, Proe. A. N. Sci., 1868. 298, not Ibid., 1836, and Transac. Am. Phil. Soc., 1859. LAELAPS AQUILUNGUIS, Cope. Loc. Cit. Leidy. 1. c. 1868. This species was described by the author from a number of bones and fragments derived from the top of the " chocolate •' stratum of Cook & Smock's upper bed of the Cretaceous Greensand of New Jersey, at a depth of about twenty feet below the surface. They were found by the workmen under direction of J. 0. Voorhees, Superin-tendent of the West Jersey Marl Company's pits, about two miles south of Barnesboro, Gloucester co., N. J. The bones preserved were portions of the under jaw with teeth, portions of the scapular arch, including supposed pubes two humeri, left femur, tibia and fibula, with numerous phalanges, lumbar sacral and caudal vertebra:, and numerous other elements in a fragmentary condition. The discovery of this animal filled a hiatus in the Cretaceous Fauna, revealing the carnivorous enemy of the great Herbivorous Hadrosaurus, as the Aublysodon 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 Aublysodon, eonstituted the most formidable type of rapacious terrestrial vcrtebrata of which we have any knowledge. In its dentition and huge prehensile claws it resembled Megalosaurns. The species is now rediscribed with additional observations and with figures. ? Zygoinatic arch.—A portion 0.5 inches in length is perhaps the malar portion of the arch rather than the squamosal, since near the termination of its inner or concave face it is pierced by a large foramen, similar in position to the suborbital foramen. The bone is slender, chiefly strengthened by a strong external, horizontal ridge, which is probably the homologue of that noticed by Prof. Owen as dividing the face of the maxillary and malar in Scelido-saurus. Alone and below this rib, the bone rapidly thins away. There is little curvature, indicating a long slender zygoma, perhaps as in Compsognathus. The foramen has not been closed above. Vertical depth inside of front of foramen. Horizontal depth zygoma, Lines. 18 15 Maxillary bone.—A portion of the right maxillary displays parts of four alveolar: three of these have a flattened oval section, while the anterior is round. suggesting the presence of a canine-like tooth. One successional tooth in place extends from the bottom of the alveolus to within .75 inch of the maxillary border; it stands obliquely in place,
- See Gegenbaur, 1. c.
