188*3.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 241 



which genera the diapophyses are wide and spreading-, while beneath, 

 the ventral apophyses are anchylosed to the centra upon which they 

 occur and hook forward over the preceding vertebral body. The pygo- 

 atyle in these and most forms of the group is somewhat elongated, of an 

 irregular quadrilateral outline, with thickened posterior border. 



Glaueionetta has very wide and spreading transverse processes to its 

 caudal vertebra 1 , and the chevron bones upon the last two are free and 

 rest mainly upon the intervertebral cartilage, as a greater series of them 

 do in the Swans. 



Turning our attention now to the consideration of the pelvis, we find 

 this compound bone in Spatula presenting us upon its dorsal aspect the 

 following points for our examination: The ilio-neural canals are com- 

 pletely closed in by the ilia meeting and ankylosing with the crista of 

 the leading sacral vertebra 1 . This is the 

 case, I believe, throughout the entire or- 

 der. On either side of this the pre-ace- 

 tabular portion of the ilium is longitudi- 

 nally concaved, each anterior border being 

 emarginated by raised bone and embel- 

 lished with a few projecting spicules. 



The post-acetabular sacral portion of 

 the pelvis is in general in the horizontal 

 plane, being pierced in an irregular man- 

 ner by a few scattered and small inter - 

 diapophysial foramina, while a median 

 farrow, deepest behiud, marks its entire 

 length. 



From this part of the pelvis the sides 

 slope gently away. The posterior margin 

 is more or less unevenly notched; the 

 notch indicating on either side, however, 

 the point of union between ilium and is- 

 chium is constant both as to occurrence 

 and location. So far as we have thus de- 

 scribed the bone it will answer in general 

 terms for the Teals, but in Glaueionetta 

 the pre-acetabular area is notably shorter, 

 while behind the bone is more spreading, 

 the interdiapophysial foramina far more 

 finally, the posterior margin is nearly even 

 the pelvis in Spatulawe find rather a large cotyloid ring, surmounted at 

 its upper and back part by a modest antitrochanter. The ischiac for- 

 amen is extensive and subelliptical in outline. Behind this we some- 

 times find, both in this species and in the Teals, a thin tract of bone, 

 which thinning may be carried to the point of forming another fora- 

 men, or a xx>st-ischiac foramen, which is quite large in some specimens, 

 Proc. N. M. SS 10 j^^ ^, (^ • 



Fig. 22. Dorsal view of the pelvis of 

 Spatula elypeata. Size of life. 



numerous and larger, and, 

 Upon the lateral aspect of 



