AND AVES OF NORTH AMERICA. 



1 73 



In the last the vertebra is broken obliquely away, leaving the condyle at one, extremity and the bind surspectant 

 zygapophyses at the other, thus demonstrating their character. In No. ;il one face of the diapophysis is straight, the 

 distal dilatation being occasioned by the expansion of the opposite margin. 



Length of diapophysis, 

 Width distally, 



Lines. 

 6 

 2 



At No. 20 there are (bur vertebrae in their natural succession, but separated and disarranged. There arc no ribs 

 near them. 



Length body a (anterior), 



" diapophysis b (from body), 



Linen. 

 4.5 

 8. 



None of the vertebrae exhibit from (lie; vertical view the breadth dependent on longitudinal alae from the zygapo. 

 physes so common among the Lacertilia. 



Of sections and views of the extremities of the vertebrae there are many. They show (lie form of the neural 

 oanal to have varied from vertically to transversely oval, and the neural arch to have been tectiform with plane 

 sides, when the canal is large, as in cervical and dorsal regions; but to have been Hat where the neural canal is 

 transverse, as in the lumbar region. Of the former kind wo have those with no, low, or elevated neural spines, and 

 the centra depressed; of the latter kind the neural spine elevated, and the centrum compressed. This form, which 

 Owen points out among the birds in the same region of Apetenodytes, occurs also, according to 11. von Meyer, in the 

 lumbal' region of I'torodactylus longipelvis Myr. Three exhibit a nearly cylindric form. Measurements of one of the 

 most compressed, from which no diapophyses proceed (perhaps lost): 



Depth of centrum, 



Width 



Depth neural canal, 



Lines. 

 2. 

 1.5 

 1. 



A transversely fractured vertebra, without centrum and with short neural spine and long diapophysis, is perhaps 

 a rib-bearing dorsal. 



Lines, 

 Depth centrum, 1.7 



Heighth spine above canal, 3. 



Of neural canal, 1. 



Length diapophysis from axis vertebra, 5.S 



There are remains of numerous long bones, but generally broken or uncharacteristic. The extremities when pre- 

 served arc generally oval, without angles or processes. Some are SO slender and straight, as to be probably referable 

 to wing phalanges. Three others are characteristic; one of theso is quite of the form of Pterodactyle humerus, 

 having an extensive proximal ala, with the transverse extent greater than the longitudinal; a slender shank and two 

 distal articular surfaces. This has belonged to a small individual; length only 7.6 lines. An equally characteristic 

 element is the ulno-radius, most probably. This is a moderately slender bom;, with two nearly equal concave artiou- 



lar surfaces at an extremity, which is slightly dilated. The other extremity has bee ore dilated, and of an elongate 



oval form, without irregularities, as far as the specimen shows. 



Length, 



Width simple extremity, 

 " shank, 

 " cotyloid extremity, 



AMERICA. PH1LO. 800. — VOL. XIV. 44 



Lines. 



14. 

 2.5 

 1.1 



2. 



