76 NEW REPTILES AND STEGOCEPHALIANS FROM 



There are two femora in the collection (Nos. 7330 and 3395, University of Michigan). 

 The first is a very small femur 73.5 mm. long, apparently of an immature individual. 

 The articular ends are imperfect, as if incomplete ossification had permitted their rapid 

 decay. The trochanter is large compared to that in larger specimens and is well formed. 

 The second femur is from the right side of a fairly large individual. It corresponds in 

 form very closely with that of R. carolinensis (fig. 29 B). 



In one small spot north of the Spur-Crosbyton road the remains of two or three 

 large Phytosaurs were found in close proximity. Most of the bones were badly weathered, 

 but a humerus, radius, and ulna were collected in close association and in good condition. 

 It has been assumed that these bones belonged to one individual, as they are of the 

 proper size and of the same side. They have been numbered 7312 in the University 

 of Michigan collection. 



The humerus (fig. 29 c) has the two articular ends of nearly equal breadth, with the 

 long axes inclined at a slight angle to each other. The deltoid ridge is broken away in 

 part, but stood nearly at a right angle to the proximal end of the bone. The shaft is 

 nearly cylindrical. The lower end has a well-developed, nearly hemispherical h'ead for 

 the radius and a distinct articular surface for the ulna. There is a distinct ectepicondylar 

 process which is not complete in the specimen. There is no entepicondylar notch 

 or foramen. The total length of the humerus is 28.35 cm.; the breadth of the upper 

 end is 14.2 cm., and the breadth of the lower end 12.7. cm. 



The radius (fig. 29 D) has a nearly straight cylindrical shaft; the upper end has a 

 well-formed concave articular surface; the lower end is but slightly expanded. The 

 total length is 24.6 cm. 



The ulna (fig. 29 E) is very broad proximally and gradually contracts in breadth to 

 the lower end. The shaft is compressed, so that it is much thinner than broad; this 

 may be, in part, due to compression. The articular face is shallow, and there is a very 

 small olecranon process. The out corner of the lower end was broken away and lost 

 and has been restored in plaster. The total length of the ulna is 30 cm. 



All of these limb-bones, as well as the femur described above, and the remains of 

 less perfect limb-bones in the collection indicate that the Phytosaurs of the region were 

 relatively long-limbed forms and must have been capable of raising the body from the 

 ground for a time at least, and also that they were capable of relatively rapid progression 

 upon the land. 



There are in the University of Michigan collection four basi-cranii of Phytosaurs, 

 Nos. 7257, 7261, 7474, and 7505. The first three show the condyle complete, the last 

 has the condyle broken away and lost. These are all typically phytosaurian in form and 

 correspond closely with Huene's description of P. kappfi as opposed to his P. rutemeyeri. 

 The general form is shown in figure 30, and plate 12, figure c, of No. 7261. All show 

 clearly the pit in the occipital condyle for the anterior end of the notochord. 



No. 7474 is the smallest, and is interesting in that it shows the lower portions of 

 the exoccipitals in position, meeting in the median line and excluding the basioccipital 

 from any part in the foramen magnum. (Plate 12, fig. D.) 



No. 7505 is the next largest. The exoccipitals are lost, and it shows clearly the 

 corrugated articular surfaces on the basioccipital for the exoccipital. The floor of the 

 brain-case is eroded and the suture between the basioccipital and the basisphenoid is 

 clearly traceable all round the bone. The edges of the shallow hypophysial cavity 

 are broken away and the entrance of the foramina for the internal carotid arteries into 

 the cavity is very clear. (Plate 12, fig. E.) 



No. 7261 is the third largest and the most perfect. The tubera basioccipitalia 

 are seen to be formed by both the basioccipital and the basisphenoid. The tubera are 



