AXIAL SKELETON OF THE PELECANLD^E. 377 



Fig. 37. Eighteenth vertebra, seen laterally. 



Fig. 38. Eighteenth vertebra, seen ventrally. 



Fig. 39. Nineteenth vertebra, seen laterally. 



Fig. 40. Nineteenth vertebra, seen ventrally. 



Fig. 41. Twentieth vertebra, seen ventrally. 



Fig. 42. Twentieth vertebra, seen preaxially. 



Fig. 43. Twentieth vertebra, seen postaxially. 



Fig. 44. Twenty-second vertebra, seen postaxially. 



Fig. 45. Twenty-third vertebra, seen preaxially. 



Fig. 46. Twenty-first, twenty-second, twenty-third, and twenty-fourth vertebrae 



together, seen ventrally. 



Fig. 47. Caudal vertebrae and pygostyle. 



(In Plates LIX., LX., & LXI., the following letters have throughout the 



meanings here given.) 



a. Sternal angle postaxial to pleurosteou (Plotut). 



at. Antitrochanterie process. 



e. Coracoid groove of sternum, 



ca. Costal angle of sternum. 



cl. Boot of furculum. 



/. Lateral acetabular fossa. 



f. Supraacetabular fossa (Pelecanus). 



g. Groove on ventral surface of ischium. 



gl. Gluteal ridge. 



h. Surface for head of rib. 



i. Ischium. 



it. Hium. 



il'. PostacetaLular part of ilium. 



k. Keel of sternum. 



Ic. Ilio-caudal spine. 



lp. Ilio-pectineal eminence. 



Ir. Eidge postaxial to posttrochanterie process (Plotut). 



LK. Lateral xiphoid. 



nix. Median xiphoid. 



p. Pubis. 



ps. Ventral process of ischium. 



*1 



s 2 . V Sacral foramina. 



.J 



st. Posttrochanteric process. 



t. Surface for tubercle of rib. 



