THE MICROSAURIAN FAMILY UROCORDYLID^E. 1 25 



indefinite. The jugal is only partially represented in the specimen, and that part 

 forms the outer boundary of the orbit. The maxillary sutures are not defined. 

 There are no evidences of teeth, since the skull is compressed dorso-ventrally. The 

 quadratojugal is, apparently, a larger element than usual, with the visual rela- 

 tions. The supratemporal lies in great part in front of the squamosal, but still has 

 the normal relations of that element. The squamosal is the characteristic feature 

 of the skull. It is very tumid at its base and projects into a long, slender, acumi- 

 nate horn, the tumid portion being ornamented by radiating striae. 



Another specimen of this species presents the greater part of the skeleton. How- 

 ever, very little can be added to our knowledge of the skull structure. It is barely 

 possible that the second specimen may be distinct from the type. The horns are 

 curved inward, but otherwise there is little or no difference. One of the most inter- 

 esting and important features of the complete specimen is the unusual preservation 

 of a leg, with impressions of 15 or more vertebra;, and traces of curved ribs which 

 are intercentral in position. 



The femur is slender and expanded at the ends, with the articular surfaces well 

 formed. The tibia and fibula are mere rods of bone, although the tibia has slightly 

 expanded extremities. There is no osseous tarsus. There are 5 digits in the foot; 

 the second one is entire and contains 4 phalanges; the other digits are incomplete. 

 The foot is remarkably long and slender, and is fully as long as the tarsal space plus 

 the tibia, with the terminal phalanx clawed. 



There are impressions of 2 oval and elongate clavicles in the pectoral region. 

 The outer end is not expanded as is usual, and the surface is ornamented with 

 grooves and ridges which radiate from a common center. 



The entire remains measure scarcely 3 inches in length and it is to be doubted 

 if the creature attained a length of more than 4 inches. It is probably a young 

 form, but there are no evidences of external gills. The chevron armature is but 

 poorly preserved, but so far as can be determined it is not different from that of 

 other Microsauria, such as Amphibamus. 



