12 Shufeldt, Osteology of Oythorhaniphtis ina^nirosiris. [,^f"]"^. 



This table goes to show that, in so far as the number of vertebrae 

 in the spine is concerned, Orthorhamphiis has, in common with an 

 Oyster-catcher, with a Sheath-bill, and with a Gull, 43 vertebrae, 

 while with their divisional lines it agrees with no one of them. 

 Finally, the only two birds that do agree in this particular — 

 both numerically and divisionally — are two Plovers, Squatarola 

 and Belonopierits, and as Plovers they are not especially closely 

 related. 



In the cervical region of the spine in Orthorhamphtis the ver- 

 tebral artery, upon either side, is generously protected by 

 extensive osseous walls, provided in the usual manner by each 

 succeeding vertebra of the neck. There is no semblance of a 

 vertebral canal, however, provided on the part of the axis or the 

 atlas, and in life the artery would appear to pass from the anterior 

 entrance of the vertebral canal of the third cervical, across the 

 axis, to within the neural canal of the atlas, and thence into the 

 cranial cavity. 



Neurapophyses appear on the second to the fifth cervicals 

 inclusive, being well developed on the atlas, but then gradually 

 diminishing in size as we follow them backward. They appear 

 again on the last three or four cervicals, small at first, until to 

 include the last one, which is more or less like one of the neura- 

 pophyses of the dorsal vertebrae. (Fig. 4. Plate II.. and fig. 8. 

 Plate IV.) 



The carotid canal is open throughout its entire course, and the 

 pleurapophysis, upon either side of it, is well developed. 



The first free cervical rib is short, and more or less rudimentary ; 

 the second is long and very slender, lacking an unciform process. 



All the dorsal vertebrcB are freely articulated with each other, 

 and this appears to be the case with all the birds mentioned in 

 this paper. Their neural spines only come in contact with each 

 other at the anterior and posterior extremities of their superior 

 free and thickened margins. There they interlock in the usual 

 manner through a pointed anterior ending and a bifurcated 

 posterior one. These spines are quadrilateral in outline, their 

 free anterior and posterior margins being concaved, thus forming 

 elliptical vacuities between them, when duly articulated as in hfe. 



Lateral processes of the dorsals are broad and flat, with all 

 their accessory projections much reduced. Only the two leading 

 dorsals possess haemal spines, and they are not very conspicuously 

 developed. 



All the dorsal ribs and one pair of the sacral ribs — the first — 

 bear epipleural appendages, and all are well developed with the 

 exception of the sacral ones. These appendages overlap the 

 succeeding ribs when articulated, and therefore materially add 

 to the stability of the osseous thoracic walls. With respect to 

 form, the ribs in Orthorhamphtis are rather slender, and this like- 

 wise applies to the six pairs of haemapophyses, which articulate 

 with the costal borders of the sternum. Of these, the longest pair 

 are those belonging to the first pair of sacral ribs : those belonging 



