MORPHOLOGICAL REVISION 



109 



The shoulder girdle (fig. 47, c): The interclavicle is rhomboidal with a strong 

 posterior prolongation; the clavicles are expanded at the anterior end and overlap 

 the interclavicle; the outer surface of the clavicles and interclavicle is not sculptured, 

 but the edge of the latter is marked by rugose striations where it is overlapped by the 

 clavicle. The distal end of the clavicle is striate. There is no cleithrum. 



The scapula is rather short and the distal is turned dorsally, almost at a right 

 angle to the coracoidal portion. There is a good-sized coracoid which takes large 

 part in the cotylus for the humerus and is separated from the scapula by a distinct 

 suture. The suture between the procoracoid and scapula is less certain, but seems 

 to have been present. There is a distinct foramen between the procoracoid and the 



Fig. 48. — Labidosaurus, X g. 



a, abdominal ribs; b, right side of ischium and pubis. No. 4876 Am. Mus. e, femur, d, outline of 

 the carpus; e, posterior limb, showing femur, tibia, fibula, and astragalus. No. 4883 Am. Mus. 



scapula. In some of the specimens the sutures between the scapula, coracoid, 

 and procoracoid have completely disappeared. 



Abdominal ribs were present as numerous small rod-like ossicles. 



The pelvis is formed by the closely united ilium, ischium, and pubis, from 

 between which the sutures have entirely disappeared in many specimens. The 

 pubis is, as in Captorhinus, very short and the pubic foramen is near the anterior 

 end; the ischium is elongate, extending a considerable distance posterior to the 

 acetabulum. Both bones lay nearly horizontal and with those of the opposite side 

 formed a typically flat and primitive pelvis. The ilium rises almost at right angles 

 to the other two bones; the upper end is somewhat expanded and projects to the 

 rear (plate 8, figs. 4, 5, 6). 



The anterior limb and foot: The humerus is relatively short, with wide proxi- 

 mal and distal ends turned almost at right angles to each other. There is a total 

 lack of the strong processes and general heaviness found in the humerus of the 



