100 



TILE EXTINCT BATRACHIA, REI'TIUA 



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 ; 



Megalosaurns, Buckland ; 



Coelosaurus, Leidy; 

 and perhaps, 



Bathygnathus, Leidy ; 



Aublysodon, Leidy. 



LAELAPS, Cope. 



PrOC Acad. Nat. Sciences, L866, p. 275; 1. c, p. 818; 1. 0. 1867, p. 284. American Naturalist, 1867, 27, 

 Dinodon, Leidy, Proc, A. N. Bci., 1868, 298, not Ibid., 1856, and Transac. Am. 1'liil. Hoc, 185!). 



LAELAPS AQUILUNGUIS, Cope. 



Loc. (.'it. Leidy. 1. c. 1868. 



This species was described by the author from a number of hones and fragments derived from the top of tl;e 

 "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 .1. 0. Voorhees, Superin- 

 tendent of the West Jersey Marl Company's pits, about two miles south of Barnesboro, Gloucester oo., N. J. The 



bones preserved were portions of the under jaw with teeth, portions of flu; scapular arch, including supposed pubes 

 two humeri, left femur, tibia, and fibula, with numerous phalanges, lumbar sacral and caudal vorfebne, 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 Badrosaurus, as the Aublysodon was related to the Trachodon of the Nebraska beds, and the 

 Megalosaurns to the [guanodon of the European Wealden ami Oolite. 



In size this creature equalled the Megalosaurus bucklandii, and with if and Aublysodon, constituted the most 

 formidable type of rapacious terrestrial vertebrata of which we have any knowledge. In its dentition and huge 

 prehensile claws it resembled Megalosaurus. The species is now rediscribed with additional observations and with 

 figures. 



? Zygomatic arch. — A. portion 6.5 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 posh ion 

 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 Compsognafhus. The foramen has not been closed above. 



Line/. 

 Vertical depth inside of front of foramen, IS 



Horizontal depth zygoma, 15 



Maxillary bone. — A portion of the right maxillary displays parts of four alveoles: three of these have a flattened 

 oval section, while the anterior is round, suggesting the presence of a. canine-like tooth. One sucoessional tooth in 

 place extends from the bottom of the alveolus to within .75 inch of t he maxillary border; it stands obliquely in place, 



*See Gegonbaur, 1. c. 



