. The structure and classification of birds . FiQ. 242.—Steenum ow Ehea (aptee Mivaet).cc^ coracoid grooves; ca, anterior lateral process ; /, keel (?) : Ix, posterior lateral process. portion is ossified as a thin spicule of bone shutting in the -foramen coracoideum. The sternum (see fig. 242) has amedian ventral prominence and two lateral thin rings of thebone, which may be indications of foramina. Three (some-times four) pairs of ribs reach the sternum. The pelvis(fig. 243) has a small pectineal process. The pubes jointhe ischia posteriorly, and anteriorly an interobturator pro-cess, of whi


. The structure and classification of birds . FiQ. 242.—Steenum ow Ehea (aptee Mivaet).cc^ coracoid grooves; ca, anterior lateral process ; /, keel (?) : Ix, posterior lateral process. portion is ossified as a thin spicule of bone shutting in the -foramen coracoideum. The sternum (see fig. 242) has amedian ventral prominence and two lateral thin rings of thebone, which may be indications of foramina. Three (some-times four) pairs of ribs reach the sternum. The pelvis(fig. 243) has a small pectineal process. The pubes jointhe ischia posteriorly, and anteriorly an interobturator pro-cess, of which there are faint indications in Struthio, unitethe two bones. Posteriorly the ilia are attached to theischia. STRUTHIONES 613 The structure of the shull of the emu ^ is not widelydifferent from that of the skull of Bhea. The vomer iswidely bifurcate behind, where it articulates both withpterygoids and palatines. The basipterygoids articulatewith the pterygoids at the extreme posterior end of the. Fig. 243.—Pelvis or Bhea (aftek Mivakt). il, nitun ; Zp, pectineal process ; af, antitrochanteric process; st, supratrochauteric process;pSf interobtiirator process ; i, ischium ; p, pubis. latter, instead of nearly halfway along them, as in otherbirds. The maxillo-palatines are hollow swollen plates,which unite with the vomer and premaxillaries, but comeapart in the dried skull. The descending process of thelacrymal has a foramen, as in Bhea. It joins the thinlamina of the ectethmoid. The descending process of the W. K. Paekek, On the Structure and Development of the Skull in theOstrich Tribe, FUl. Trans. 1868, p. 113. L L 514 STRUCTURE AND CLASSIFICATION OF BIRDS nasal is only represented in the specimen before me by aminute pointed bit of bone attached above to a point cor-responding to that whence the naso-maxillary arises inBhea. DromcBus has twenty cervical vertebrce. The atlas is


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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbirds, bookyear1898