COPE ON GEOLOGY AND VERTEBRATE FOSSILS. 593 



The next bones, marked as Nos. 1 and 2 in my notes, are from the 

 median line of the skull, and of very peculiar form. Tliey were found 

 in contact, but it is very doubtful whether the relation they present to 

 each other is the normal one. ISTo. 1 is an L-sliaped bone, the short 

 limb of the L being recurved, and with tlie extremity pointing nearly in 

 the direction of the longer limb. The region at the junction of the L is 

 the thickest, being very massive and solid, and the limbs contract reg- 

 ularly to their extremities. The shorter limb becomes compressed 

 toward the end. The longer narrows more gradually, and is convex 

 transversely on the face next the shorter limb. The other face of the 

 long limb exhibits two longitudinal excavations, separated by a vertical 

 septum. The opposite face of the short limb is transversely truncate. 

 The posterior part of the inferior face of the long limb is also flat, and 

 joins that of the short limb at a transverse solid angle which is a little 

 less than right. In profile, the adjacent faces of the two limbs of the 

 L form a deep, rounded sinus. These and the adjacent lateral surfaces 

 are roughened with grooves, some of them of large size, apparently for 

 blood-vessels. The convex side of the long limb is still rougher, being 

 transversely wrinkled, and pierced by numerous pores. Its distal third 

 is equally divided by a strong median groove. 



Bone No. 2 is composed of two elements, one of them entire, the other 

 incomplete. The former consists of two triangular plates united by their 

 longest borders so as to give a V on section, and to inclose together a deep 

 groove whose sides are elevated at one end and gradually descend to 

 the other. The line of junction is a narrow, obtuse keel, and the exter- 

 nal surface is furrowed by grooves which are parallel to the shortest 

 sides. This sheath-bone incloses a slightly curved longitudinal element, 

 which extends freely from it at its long angle, as a rod with an oval 

 section, and is nearly continuous with the keeled angle of the embracing 

 bone. In the other direction, it becomes wider and deeper, to the pos- 

 terior border of the broken sheath- bone. Here it does not fill the 

 sheath-bone, but roofs over the inclosed space, which forms a conical 

 axial cavity of the mass, which is now filled with matrix. The surface 

 away from the sheath-bone is gently concave, and is divided longitu- 

 dinally by the base of a septum, or keel. The opposite surface of the 

 free part of the median bone is equally divided by a longitudinal groove. 



Positive determination of these elements is at present impracticable, 

 as they do not resemble the corresponding bones in any animal known 

 to me. '^0. 1 approximates in form the ethmoid of the Gull {Larus), but 

 appears, in part at least, to have been a bone of the external surface. 

 The long limb has nearly the appearance of those parts of the Bird's 

 skull which are inclosed in a horny sheath; the inferior septum is not 

 appropriate to that element. Its proper position at the front of the 

 basicranial axis is less probable, because bone No. 2 is more appro- 

 priately- placed there. If we then suppose No. 1 to be the septum 

 narium and adjacent part posterior to it, we are met with the anoma- 



