clxx GENERAL SUMMARY OF SCIENTIFIC AND 



power of flight. One group thus afFected has been lately elucidated 

 by Messrs. A. and E. Newton in a memoir " on the Psittaci of the 

 Mascarene Islands." It appears that each of the four islands of that 

 group had at one time at least two species of parrots, among which 

 were even two generic types; one {Necropsittacus rodericmius) con- 

 fined to Rodriguez, and another {Lophopsittacus mauritianus) restrict- 

 ed to Mauritius. These two are now known only from their fossil re- 

 mains save that in one case (LojjJiopsittacus) the external characters 

 are traceable from a figure made by an old Dutch traveler. The other 

 species have also become exterminated, or exist in diminished num- 

 bers. Thus in Mauritius one is entirely extinct, and another exists 

 in decreased numbers; from Reunion two formerly indigenous spe- 

 cies have entirely disappeared ; in Rodriguez one species is now also 

 entirely extinct, and another nearly so ; and only in the Seychelles 

 Islands are the two species found in any number, but even they are 

 receding, and apparently doomed to the fate of their relatives. 



A study of these several memoirs, and the data on which they are 

 based, and especially a comparison of the measurements of the in- 

 sular species thus referred to with those of continental areas, reveals 

 the fact that the island forms have at least a decided tendency to 

 abbreviation of the wings and develojDment of the legs in proportion 

 to each other as well as to the bill. These characteristics, it is true, 

 have not been adverted to in the memoirs enumerated ; but they be- 

 come evident upon a comparative examination of the species signal- 

 ized by them and allied continental ones. The restriction of the 

 areas and the paucity of carnivorous enemies, which detract from the 

 necessity of flight, and induce the greater use of means of terrestrial 

 progression, are doubtless the determining causes of these peculiari- 

 ties. 



For the class of mammals one discovery merits sjDecial mention, 

 and several monographs of different families or genera of special in- 

 terest have been published. 



The order of Monotremes^ the lowest and most generalized tyjje of 

 mammals, and which dificrs in the most marked manner from all 

 other types of the class, has hitherto been suf)posed to be confined 

 to Australia in the present geological epoch. In that continent it 

 has furnished two very distinct forms or representatives of distinct 

 families Tachyglossus, or Echidna, and Ornithorliynchus. During the 

 past year, however, the collectors of Mr. Bruijn, of Ternate, obtained 

 from natives, on a peak of the Arfaks called Mickerbo, in the 

 island of New Guinea, two imperfect skulls of a mammal which 

 evidently is a typical member of the family Tacky glossidoe. This has 

 very lately (December 3, 1876) been described by Messrs. W. Peters 

 and G. Doria as a new species of the genus Tachyglossus, under the 

 name T. Bruijnii. It nevertheless differs markedly from the T. hys- 

 trix and T. setosus of Australia in the much more elongated and 



