NATURAL SCIENCES OP PHILADELPHIA. 229 



and tbe sea-tnrtles, they are covered with large scutes, four in 

 number, as in Baena arenosa. The intermediate vertebral scutes, 

 are longer than broad — the third being 4 inches long, and 3i 

 inches wide. A peculiarity of the species is the undulating 

 manner in which the costal scutes join the marginal scutes, and the 

 sternal scutes one another. The species may be named Baena 

 undafa. 



Dr. Carter's collection also contains some fragments of bones 

 of a large mammal, which are so mutilated as to be hardly charac- 

 teristic. A jaw fragment among them, with the retained fragments 

 of the true molars, would appear to indicate a species of Palseosyops 

 much larger than P. paludosus. In absence of other evidence, it 

 might be viewed as a species of this genus, under the name of 

 P. major. The true molars occupied a space of four and a half 

 inches. The last molar measured an inch and seven-eighths fore 

 and aft, and an inch transversely in front. 



Dr. Carter had also sent some fossils to Prof. Leidy, among 

 which were portions of jaw^s, with nearly full series of teeth of 

 Hyrachyus agrarius. This animal is related to the Tapir, Hyra- 

 codo7i, and Lophiodon. The formula of its dentition is the same 

 as in Hyracodon: 7 molars, 1 canine, and 3 incisors. The true 

 molars are like those of Lophiodon^ except that the last lower one 

 has a bi-lobed instead of a triple-lobed crown. Apparently the 

 same animal has been indicated by Prof. Marsh, under the name 

 of Lophiodon Bairdianus. A fragment of a lower jaw containing 

 the last premolar, and the first true molar, indicates a larger 

 species of Hyrachyus^ which ma}^ be named H. eximius. The 

 crown of the last premolar is 7^ lines antero-posteriorly, and 5^ 

 transversely. The true molar has measured about 8^ lines fore 

 and aft, and 6 lines transversely. The depth of the jaw fragment 

 below the true molar is over an inch and a half. 



Another fossil is a mutilated incisor, indicating a species of 

 Trogosus rather more than half the size of T. castorideyis, which 

 may be named T. vetidus. 



A femur of Palseosyops paludosus, in the collection, exhibits 

 the third trochanter, characteristic of the unequal-toed pachyderms. 

 The astragalus of this animal almost repeats that of the living 

 Tajsirs. 



Among the remains of Dr. Corson's collection, there is the 

 greater part of the lower jaw of a large crocodile, but too much 

 broken to attempt to give an opinion in regard to its specific 

 character, until it is in some degree mended or restored. 



1871.] 



