THE MICROSAURIAN FAMILY SAUROPLEURID^. 



159 



Cope referred to 5. scutellata the larger part of an individual with strongly 

 developed ventral scvxtellation. This he figured on plate xxxvi, fig. 2 (123). 

 Even a cursory glance will, however, suffice to show that the sculpturing of the 

 clavicle just described and that exhibited by the specimen there figured are identical. 

 Closer examination shows important differences between the species, the principal 

 distinctions being the strongly developed ventral scutellag in Sauropleura scutellata, 

 the difference in form and sculpture of the interclavicles, and the posterior extension 

 of the interclavicle in S. scutellata which is wanting in 5. pauciradiata. The sculp- 

 turing of the interclavicle in the form figured by Cope as S. scutellata, just referred 

 to, is identical with the sculpture of the clavicles, as would be expected. The ridges 

 on all of the pectoral elements of 5. pauciradiata are strong and are rather few in 

 number, while in S. scutellata the sculpturing is more in the form of interrupted 

 grooves. 



The specimen (plate 14, fig. 3) exhibits the great part of the body with one fore 

 limb. The skull is wanting. The belly was very broad and strongly protected by 

 broad, long scutes arranged en chevron. The scutes are close together and form a 

 compact ventral armor for the animal. The fore limb is very weak. The humerus is 

 represented by its distal end only. The radius and ulna are very short and weakly 

 developed in comparison to the size of the animal. The limbs could not have sup- 

 ported the animal on land and served, probably, 

 merely as organs of equilibration, for the animal 

 was undoubtedly aquatic. The fingers are not 

 all preserved and there is no carpus. 



Numerous other remains formerly associated 

 with 5. scutellata are here referred to S. pauci- 

 radiata, on account of the strongly developed 

 ventral armor, which is different from that of 

 the type of S. scutellata. The remains do not, 

 however, add to our knowledge of the anatomy 

 of the forms, as they are very fragmentary. 



Two skulls are provisionally associated with 

 this species. One of these skulls is figured by 

 Cope (123) on plate xxxiii, fig. i. It is there 

 referred to S. scutellata. That it can not, how- 

 ever, be referred to that species is manifest when 

 the teeth are observed. In the type of S. scutellata the teeth are very small, sharp 

 denticles, while in the skull under discussion the teeth are well developed and their 

 bases are longitudinally grooved. The teeth are elongate in the anterior part of the 

 skull and are shorter posteriorly. They are, however, all strong. The skull is acu- 

 minate and the orbit is located about midway of its length. The jaw is slightly longer 

 than the cranium. The structure of the cranium can not be determined in either 

 skull, and in one only the position of the orbits and the teeth. 



Fig. 3j. 



A. Interclavicle of Sauropleura pauciradiata 



Cope. X I. (After Cope.) 



B. Left clavicle of Sauropleura pauciradiata 



Cope. X I . (After Cope.) 



