254 General Notes. [March, 



lodon % AmpJiisaurus, and other species with digitigrade feet, 

 small fore limbs, and prehensile claws, form the order Theropoda, 

 which has also two sub-orders — Ccemria and Campsognatha. The 

 Hallopoda are doubtfully referred to the sub-class, and have the 

 hind feet specially adapted for leaping. 



In the preparation of his papers on this subject Professor Marsh 

 has had very extensive material, and has had excellent opportuni- 

 ties for investigation. He had added more to our knowledge of 

 this division of reptiles than perhaps any other single person. 

 His demonstration of the structure of the pelvis in various genera, 

 of the feet in many forms, includii r,and the dis- 



covery of the clavicle in Iguanodon and other genera, are among 

 the most important points gained. It is, however, not evident 

 that the Dinosauria constitute a group of higher rank than an 

 order, or that the subdivisions proposed by Professor Marsh are 

 of higher rank than sub-orders or families. 



The "personal equation" is observable in this work, in as 

 marked a degree as in any of Professor Marsh's papers. This is 



First. In his failure to characterize his genera on first publish- 

 ing them — a proceeding which is apparently intended to warn 

 others off the field. The publication of nomina nuda, without the 

 definitions which enable others to use them, is, to say the least, 

 very inconvenient to cotemporary students. 



Second. In his failure to recognize the labors of others, except 

 to point out supposed errors. Thus three of his orders had re- 

 ceived names long before Professor Marsh wrote, and had been 

 defined, less completely, it is true, but, as far as the material went, 

 correctly. Thus his S;iump<>d;i was named by Owen, in 1841, 

 Opisthoccela ; his Ornithopoda by Cope, in 1869, Orthopoda; and 

 his Theropoda by Cope, in 1869, Goniopoda. The numerous gen- 

 era described from the American Jurassic by American authors, 

 are all ignored or stated to be founded on error. 1 Some of them are 

 identical with those proposed by Marsh, and of earlier date. ■ 



Thirdly. In his failure to credit others with their discoveries, 

 and permission of the inference that they are his own. Such is 

 the discovery of the hyposphen articulation, by Cope, which he re- 

 names the diplosphen. Such is the discovery of the sternum in the 

 Dinosauria, which was made by Cope in the Laramie genus Mono- 

 donius in 1877 (Proceedings Philadelphia Academy). His ref- 

 erence of some discoveries to other than their authors is not less 

 frequent. Thus it is well known that Professor Cope first showed 

 the bird-like, affinities of some of the Dinosauria, and affirmed 





