256 DESCRIPTION OF FIVE NEW SPECIES 



Ornithoidichnites Sillimani. * Toes three, all in front ; spreading 

 from thirty to forty degrees : tuberous expansions usually distinct : 

 two on the inner toe : three on the middle toe ; and four on the 

 outer toe. Claws very distinct, an inch long. Length of the mid- 

 dle toe, five inches : of the whole foot, six to seven inches : of the 

 step, eighteen to tweftty inches. The whole foot more slender and 

 delicate in its proportions than the O. tuherosus. 



PI. XI, fig. 2 shows two small tracks of O. Sillimani in relief, 

 from Turner's Falls : the specimen being in the possession of Dr. 

 Deane. The track is considerably smaller than this species usu- 

 ally is, and some parts of the toes are wanting : but other parts 

 are remarkably distinct. It would seem that these tracks were 

 made by the animal when standing still : and I have given a 

 drawing of them for this reason ; because it is nearly a solitary 

 example of such a position of the feet. 



The O. Sillimani is found at most of the localities of foot- 

 marks in this valley. 



The second new species which I have to describe, is a small 

 Leptodactylous track, from the Horse Race in Gill, three miles 

 higher up the river than Turner's Falls, and long known as a fine 

 locality of footmarks. I dedicate it to my friend, Prof. Henry 

 D. Rogers of the University of Pennsylvania; whose able and 

 successful labors as a geologist, eminently entitle him to such a 

 mark of respect. The following is a description of the species. 



- Ornithoidichnites Rogersi. Toes four, three of them in front : the 

 lateral ones spreading about seventy-five degrees : length of the 

 middle toe, seven eighths of an inch. Hind toe nearly on a line 

 with the outer one ; seven eighths of an inch long. Entire length 

 of the foot, including the hind toe, one inch and three quarters. 

 Length of the step, from three to four inches. Shown of the natu- 

 ral size on PL XI, fig. 7. 



This species approaches the O. gracilior of my Report, But 

 it is much smaller, and the liind toe is a good deal longer in pro- 



* I am a'W'are that in such a case as that in the text, the best rules require the name of 

 the individual to be expressed adjectively. But for reasons that cannot here be given, I 

 prefer tlie genitive form ; and I believe this is not without abundant authority. 



