four other new Sjpecies of Cretaceous Birds. 213 



pelvis, several cervical and caudal vertebrae, and numerous 

 ribs, all in excellent preservation. Fragments of four other 

 individuals were also found bj the writer, which agree essen- 

 tially with the corresponding parts of the more perfect skeleton. 

 An examination of these various remains soon makes it 

 evident that they represent a gigantic swimming bird, having 

 its nearest living allies probably in the Colymbidce^ but differ- 

 ing widely in many respects from that group, and from all 

 other known birds, recent and extinct. 



The femur is unusually short and stout, much flattened 

 antero-posteriorly, and the shaft curved forward. It some- 

 what resembles in form the femur of Colymbus torquatus^ 

 Briinn., but the great trochanter is proportionally much less 

 developed in a fore-and-aft direction, and the shaft is much 

 more flattened. The tibia, or tibia-tarsus, is straight and 

 elongated. Its proximal end has a moderately developed 

 cnemial process, with an obtuse apex. The epicnemial ridge 

 is prominent, and continued distally about one half the length 

 of the shaft. The distal end of the tibia has on its anterior 

 face no ossified supratendinal bridge, differing in this respect 

 from all known aquatic birds. The fibula is well developed, 

 and resembles that of the Divers. 



The tarso-metatarsal bone is much compressed transversely, 

 and resembles in its main features that of Golymhus. On its 

 anterior face there is a deep groove between the third and 

 fourth metatarsal elements, bounded on its outer margin by a 

 prominent rounded ridge, which expands distally into the free 

 articular end of the fourth metatarsal. This extremity projects 

 far beyond the other two, and is double the size of either, thus 

 showing a marked difference from any known recent or fossil 

 birds. There is a shallow groove, also, between the second 

 and third metatarsals, which, taken in connexion with the 

 deeper one, made the specimen appear, while still in the rock, 

 as if its main elements were separate. The second metatarsal 

 is much shorter than the third or fourth ; and its trochlear end 

 resembles in shape and size that of the former. The ex- 

 istence of a hallux is indicated by an elongated oval in- 

 dentation on the inner margin above the articular face of the 

 second metatarsal. The free extremities of the metatarsals 

 have the same oblique arrangement as in the Golymhidce, to 

 facilitate the forward stroke of the foot through the water. 

 There are no canals, or even grooves, for tendons on the 

 posterior face of the proximal end, as in the Divers and most 

 other birds ; but below this there is a broad shallow depression 

 extending rather more than halfway to the distal extremity. 



The phalanges of the large external toe are very peculiar, 



