384 Annals of the Carnegie Museum. 



fore be known as Trachodoii aunectciis, restricting for the present the 

 genus Claosaurits to the form from the Pteranodon beds, which latter 

 however if eventually shown to be generically identical with T. 

 (^C/aosaiirus) aiinectens, as Marsh supposed, will then have to be 

 referred to Tracliodon, resulting in the abandonment of the genus 

 Ciaosaunis as a synonym of Trachodon. 



Trachodon ( Claosaurits^ annectens is further noticed by Professor 

 Marsh in August, 1S92, ■' and in October of the same year." In the 

 latter communication he gives a restoration of the skeleton based upon 

 the excellent material at his command. In January, 1893, he gives a 

 description of the skull and brain.'' In 1890,'* Professor Marsh pro- 

 posed for these dinosaurs the family name Trachodoutidce to replace 

 the Hadrosaitridc2 proposed by Cope in 1869,'' to which family these 

 dinosaurs had already been referred. Later he includes in the Traclw- 

 dontidcc only such genera and species as had been proposed by Leidy 

 and Cope, placing the genus Ciaosaunis in a new family, the Clao- 

 sauridce ■^" on very insufficient grounds. There can be no question con- 

 cerning the synonymy of the family name Claosaurida with that of 

 Trachodontido', which is to be preferred to that of Hadrosauridcv since 

 the genus from which the latter was derived becomes a synonym of 

 Trachodon. It is doubtful, however, whether the family name Tracho- 

 dontlda should not be abandoned in favor of I^^uanodontida, which has 

 priority and was proposed for the reception of the European forms. 

 Iguanodontidai would then include both the American and European 

 forms of these closely related dinosaurs. 



Following is a list of the various genera and species of Trachodon- 

 tidas that have been proposed, with author's name and a reference to 

 the original description of each. 



Trachodon niiralnlis Leidy, Proc. Phil. Acad. Sci., March, 1856, 

 p. 72. 



Thespesius occidentalis Leidy, Proc. Phil. Acad. Sci., December, 

 1856, p. 311. 



2' See Am. Jour. Sci., Vol. XLI V., August, 1892, pp. 171-173, Plates II. and III. 

 ■^^Ibid., Vol. XLIV , October, 1892, pp. 343-346, Plate VI. 

 '^^ Km. Jour Sci., Vol. XLV., Jan., 1893, pp. 83-86, Plates IV. -V. 

 " Ibid., Vol. XXXIX., 1890, p. 424. 

 ^'^ See Proc. Phil. Acad. Sci., 1S83, p. 99. 



^f" See Am. Jour. Sci., December, 1895, p. 498, and Dinosaurs of North America 

 l6th Ann. Rep. U. S. G. S , p. 244. 



