NEW PALEOZOIC VERTEBRATA. [Feb. 5, 



This is the smallest species of the genus. It differs besides from 

 the C. ptmctoUneatum in the smoothness and acuteness of its horns, 

 and in the weaker sculpture, where visible. It has the orbits more 

 anterior and the horns shorter than in the still larger C. divarica- 

 tmn.^ The specimen shows that in this species, and probably in 

 the others referred by me to this genus, both limbs are present ; 

 that the thoracic buckler and ribs are present, and that the spines 

 of the vertebrae, though wide, are not sculptured. The digits are 

 long and were probably connected by a natatory web. The block 

 on which the specimen lies, contains several scales of fishes of the 

 genus Coelacanthus. From Cannelton, Pa., Mr. R. D. Lacoe. 



Sauropleura latithorax, sp. nov. PL III, Fig. 4. 



Represented by the anterior half of the animal, with the skull, 

 on a block of coal shale from Linton, Ohio. The superior aspect 

 of the ventral armature and of the thoracic shields is displayed, 

 with the superior surface of the skull. The vertebral column is 

 therefore wanting, but a number of ribs are preserved, as are also 

 parts of both anterior limbs. Hind limbs wanting. 



In the characters of its ventral armature, ribs and extremities, 

 this species agrees with the type of the genus Sauropleura, S. digi- 

 tata Cope. In the character of the skull, thoracic and ventral 

 armature, and limbs it agrees with the genus Colosteus Cope. It is 

 probable that the latter name must be regarded as a synonym of 

 Sauropleura (as I have suggested in the paleontology of the Geol. 

 Survey of Ohio, 1874, p. 406), although further material will be 

 necessary to determine this point positively. < In any case it may be 

 assumed that Sauropleura had a thoracic armature from marks on 

 the original specimen, and this is the only character in which it 

 was supposed to differ from Colosteus, where it is present. 



The ventral armature consists of longitudinal series of short 

 scales, which series form chevrons directed forwards. The median 

 scales are rounded in front on the superior side, viewed from above. 

 The thoracic shields are rather wide for their length. The inter- 

 clavicle (? praesternum) is rounded posteriorly, with a regularly 

 oval outline, and the width is subequal for a distance anteriorly 

 equal to the width. Each of the clavicles is as wide as the inter- 

 clavicle posteriorly. The anterior extremities of all are concealed in 

 the matrix, and the sculpture cannot be made out, as only the supe- 



iCope, 



