AND AVES OF NORTH AMERICA. •>:', 



Pectoral bones with strong elevated radii and very weak reticulation in the centre of 

 the median. The abdominal scales thick, many in a transverse series. 



C. CRABSISCUTATU8. 



Pectoral bones nearly as above; the abdominal scales slender, not more than three in 

 a lateral transverse series. 



C. MARSHII. 



Pectoral bones — the lateral finely pitted, the pits becoming elongate towards the 

 margin. 



C. FoVEATUS. 



COLOSTEUS CRASSISCTJTATITS, Cope. 



One of the specimens of this species consists of a supero-lateral view of a crushed cranium and anterior part of 

 the body. The median pectoral bone appears as a sagittiform plate with thin edges, rounded lateral angles and a 

 thin median prolongation behind. The greater part of the borders of the right orbit are distinct, and display the 

 continuity of the malar and supratemporal regions. The ramus mandibuli is longer than the cranium proper. The 

 number of the teeth cannot be determined, but they are rather large, and traces of their existence do not extend 

 behind the orbits. The length of the long anterior mandibular tooth is .5mm., and the diameter at the base .1mm. 

 Diameter of base of a superior maxillary .'2mm. The approximate length of the mandibular ramus is .0715m. long ; 

 longitudinal diameter of the orbit 73mm. ; length of median pectoral plate .03Gm. ; width of same .019m. 



Other specimens (Nos. 4 and 10 coll. J. S. Newberry) show that the abdominal scutellation commences 

 immediately behind the pectoral bones. Those near the median line are similar to the external, and they unite in a 

 zigzag line. The depth of these scales is oblique, and is somewhat greater than the width. Thus one angle 

 projects, and gives the surface a somewhat ribbed rather than continuous character. The following measurements 

 express their dimensions relative to other portions of the body. 



M. 



Width of median pectoral. .0138 



Do. three pectorals restored, .054 



Do. scale band, .064 



Scales in .01m. transversely to series, 5.2 



Do. longitudinally do., 1.75 



Radii of lateral pectoral crossed by .01m., 7 . 



Length ulna and radius, .0108 



Do. metacarpus, .000 



The above measurements express the small size and weakness of the fore limb. Another specimen (No. 18) in 

 which the impressions of the scales are of the same size as those of the preceding, the impression of what may be 

 femur and ulna and radius are visible, which are of considerably smaller size than the one above mentioned. They 

 are but doubtfully these elements. 



M. 



Length proximal element, 004 



Do. two distal do., .0038 



A median pectoral plate of a seventh and much larger individual than the preceding is prolonged anteriorly 

 and posteriorly. The broad posterior portion is transversely ribbed, the ribs weaker and interrupted medially. 

 Length .063m.; with .04m. 



This very interesting form is part of the unique and important collection made by Prof. J. S. Newberry, at 

 Linton, Columbiana County, Ohio. 



