On the Species of the Genus Plotus. 41 



VII. — On the Species of the Genus Plotus and their 

 Distribution: By H. B. Tristram, D.D., F..R.S. 



(Plate III.) 



There are few groups in ornithology more distinct than the 

 subfamily Plotinse — so sharply marked that not an aberrant 

 Cormorant on the one side, or Tropic-bird on the other, has 

 ever been suspected of balancing itself on the boundary-fence. 

 Yet even this self-contained group has not escaped the fate 

 of all others, of being subdivided into baseless species. The 

 genus Plotus is usually held to contain four species : — 



(1) P. anhinga, L., extending through the temperate and 

 tropical regions of the vrhole New World. 



(2) P. levaillanti, Licht., hitherto supposed to be confined 

 to Southern, Western, and Central Africa. 



(3) P. melanoy aster, Gm., inhabiting the whole Indian 

 region and Madagascar, 



(4) P. nov<B-hollandi(B, Gould, from Australia. 



It is difficult, from the specimens in the British Museum, 

 to distinguish this last bird from P. melanogaster. Gould, in 

 his description, gives as the diagnosis of the species (P. Z. S. 

 1847, p. 34) — "^'Very closely allied to the Plotus inhabiting 

 Java, but distinguished from it by the shortness of the scapu- 

 laries and by its larger size.^' On examining the series in 

 the Museum, I do not find any such constant differences. 

 The largest Chinese specimen equals the smallest Australian 

 in both respects. I am inclined to agree with Sclilegel 

 (Mus. des Pays-Bas) in specifically uniting the Australian 

 with the Indian bird. 



During my journey through Northern Syria in 1881, it 

 was my good fortune to discover a colony of Plotus breeding 

 in the Bahr el Abiad, or Lake of Antioch. I brought this 

 fact before the notice of the Zoological Society, and exhibited 

 a male specimen in full breeding-plumage and the eggs ob- 

 tained by me (P. Z. S. 1881, p. 826), identifying the bird 

 with the African P. levaillanti, and not with the Indian 

 species. I gave a further description of this colony in ' The 

 Ibis' (1882, p. 418). 



