96 MH. W. p. PTCRAFT ON THE [Feb. 15, 



b'. Furculum not fused with carina sterni ; precoracoid feebly developed. 

 a'-. Carina scarcely extending beyond the middle of the corpus sterni. 



Pkakicrocora.r. 

 i'^. Carina three-fourths as long as corpus sterni PMhs. 



0. Sternum broader than long, carina extending the whole length of corpus 

 sterni. Furculum fused dorsally with the head of the coracoid and 

 ventrally with the carina sterni Fregoia. 



D. Pelvic G-irdle (figs. 3 & 4, pp. 88 & 89). 



A. Pelvis nearly as broad as long. Ilia widely separated one from another 



by the transverse processes of the synsacrum. Preilium narrow, postiliura 

 presenting a broad surface dorsally ; about half of the total length of the 

 pubis free, projecting beyond the postero-inferior angle of the ischium. 

 Obturator foramen about twice the diameter of acetabulum. 



a. Anterior and posterior renal fossae separated one from another by a low 



ridge, and not divided up into compartments by ventral transverse 

 processes of the synsacrum Phaethon. 



b. Posterior renal fossa separated into a number of narrow compartments 



by the ventral transverse processes of the synsacrum Frcgata, 



B. Pelvis much longer than broad. Preilia meeting in the mid-dorsal line, 



postilia not widely separated and presenting a broad dorsal surface. 



c. Pelvis more than twice as long as broad; dorsal surface of postiliura 



very broad. Ischiadic foramen about three times as long as the 

 diameter of the acetabulum. Preilium of about equal width throughout, 

 postilium presenting a broad dorsal surface ; rather less than a fourth 

 of the total lengih of tlie pubis free and projecting beyond the postero- 

 inferior angle of the ischium, almost directly backwards. Anterior 

 renal fossa deep, its length equal to the depth of the ischiadic foramen. 



Obturator foramen nearly closed by bone Pekcamis. 



(I. Pelvis about three times as long as broad; dorsal surface of postilium 



moderately broad. 



a'. Ischiadic foramen nearly or quite five times the diameter of the 



acetabulum. 



«-. Preilium of about equal width throughout or with a very slight 



expansion cephalad ; postilium presenting a moderately broad 



dorsal surface ; about one-third of the total length of the pubis 



projecting beyond the po.stero-inferior angle of the ischium. 



Anterior renal fossa deep, moderately wide, length nearly or quite 



equal to the depth of the ischiadic foramen. Obturator foramen 



nearly or quite surrounded by bone Sula. 



b^. Preilium much expanded cephalad ; about one-fourth total length of 

 the pubis free, and turning downwards and inwards almost at a 

 right angle at the postero-inferior angle of the ischium. Anterior 

 renal fossa extremely narrow, length about equal to the depth of 

 the ischiadic foramen. Obturator foramen not shut off from 

 obturator fissure by bone Phalacrocorax. 



h' . Ischiadic foramen about twice as long as acetabulum. Preilium much 

 expanded cephalad ; inferior border notched ; dorsal surface of post- 

 ilium with its outer border forming a thin raised edge to the dorsum 

 of the pelvis ; with a strong ridge from the post-trochanteric process 

 forwards to meet its fellow in the middle line ; about one-fourth of 

 the total length of the pubis projecting beyond the postero-inferior 

 angle of the ischium ; anterior renal fossa small, pyriform. Obturator 

 foramen nearly or quite shut off from the obturator fissure. 



Plotus, 



