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NEW YORK STATE MUSEUM 



caved, each anterior border being emarginated by raised bone and 

 embellished with a few projecting spiculae [see fig. 21]. 



The postacetabular sacral portion of the pelvis is in general in 

 the horizontal plane, being pierced in an irregular manner by a 

 few scattered and small interdiapophysial foramina, while a median 

 furrow, deepest behind, 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 in- 

 dicating on either side, however, that 

 the point of union between ilium and 

 ischium is constant both as to occur- 

 rence and location. So far as we 

 have thus described the bone it will 

 answer in general terms 'for the teals, 

 but in Clangula the preacetabular 

 area is notably shorter, while behind 

 the bone is more spreading, the inter- 

 diapophysial foramina far more nu- 

 merous and larger, and, finally, the 

 posterior margin is nearly even. 

 Upon the lateral aspect of the pelvis 

 in Spatula we find rather a large 

 cotyloid ring, surmounted at its upper 

 and back part by an antitrochanter 

 of no great size. The ischiac fora- 

 men is extensive and subelliptical in 

 outline.* Behind this we sometimes 

 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 foramen, or a 

 postiscliiac foramen, which is quite 

 large in some specimens. 

 In all the Anatinae that I have examined, a propubis is to be 

 found jutting forward from its usual site. This is the case in 

 Spatula. Behind this a small obturator foramen, nearly closed in, 

 is to be noted, while the obturator space is very large and com- 

 pletely surrounded by bone behind, through the footlike process 

 afforded by the ischium. This latter projection articulates with a 

 facet, intended for that purpose, on the upper border of the post- 

 pubis [see fig. 22]. 



Fig. 21 Dorsal view of the pelvis of 

 Spatula clypeata. Natural size 



