NO. 9 A NEW PLIOCENE STORK SHORT 5 



are sufficient to warrant generic distinction for this species. Similari- 

 ties with fossil species not represented by tibiotarsi remain to be 

 demonstrated. 



COMPARISON OF THE FOSSIL WITH LIVING STORKS 

 AND THEIR FOSSIL CONGENERS 



The following specimens were used in comparison with the fossil 

 tibiotarsus : Mycteria americana, 10 ; Euxenura galatea, 2 ; Dissoura 

 episcopus, 3 ; Xenorhynchus asiaticus, 1 ; Anastomus lamelligerus, 1 ; 

 Ibis cinereus, 2 ; Ephippiorhynchus senegalensis, 1 ; Ciconia ciconia 

 ciconia, 4 ; C. c. boyceiana, 1 ; C. nigra, 2 ; Jabiru mycteria, 10 ; 

 Leptoptilos dubius, 2; L. javanicus, 2; Sphenorhynchus abdimii, 1. 

 These species represent all genera listed by Peters (1931). Among 

 living storks Dissourodes milleri shows some major similarities with 

 Dissoura episcopus, Jabiru mycteria, Ciconia ciconia and C. nigra, 

 and Euxenura galatea. 



The tibiotarsus of Dissourodes differs rather strikingly from Xeno- 

 rhynchus asiaticus in proportions of the condylar head of the bone. 

 In the latter species the head of the bone is deep and narrow, with 

 little evidence of lateral displacement of the inner condyle. The 

 intercondylar groove is proportionally narrower, and the external 

 ligamental process is much more elongate than that of D. milleri. 

 A fossil species, Xenorhynchus nanus (De Vis, 1888), is more like 

 Dissourodes but is peculiar in the great size of its tendinal groove. 

 The two mycteriine genera, Mycteria and Ibis (cinereus) have the 

 condylar heads of their tibiotarsi shaped generally like Xenorhynchus 

 and so differ in a similar manner from the fossil. Their intercondylar 

 grooves are peculiar in being V-shaped anteriorly but sharply shift- 

 ing to a U-shape near the base of the groove. The distal tendinal 

 groove opening is circular, not oval, in these genera, the species are 

 much smaller than Dissourodes milleri, and the latter's tibiotarsus 

 is generally much more massive. Anastomus lamelligerus differs from 

 the fossil in many respects including its differently shaped inter- 

 condylar notch and shallow anterior condyles, longer supratendinal 

 bridge, round distal opening of the tendinal groove, much more 

 rounded posterior articulating face of the condylar head, and its 

 much smaller size and less massive structure. 



Modern species of Leptoptilos differ in tibiotarsal conformation 

 from Dissourodes. The shaft in the latter is proportionally more 

 massive in relation to the size of its condylar head, although repre- 

 senting a species smaller than those of modern Leptoptilos. Fossil 



