NA TURE 



91 



THURSDAY, NOVEMBER 26, igoS. 



EXTINCT FRENCH BIRDS AND AMERICAN 



TORTOISES. 

 Li's Oiscaiix Jcs Phosphorites dii Oucrcy. By C. 



Gaillard. Annales de I'Universite de Lvon, nouv. 



sorie : I., Sciences, Medicine, Fascicule xxiii. 



Pp. 1-178; plates i-viii. (Lyon: A. Rev et Cie. ; 



Paris : J. B. Bailliere et Fils, 1908.) 

 The Fossil Turtles of North America. By O. Perry 



Hay. Pp. iv+568; plates i-cxiii. (\A'ashington : 



Carnegie Institute, 1908.) 

 "XT THEN working at the vertebrate remains from 



» » the phosphorite beds of Central France, the 

 late Dr. Filhol made over the whole collection 

 of bird-bones from these deposits in his possession to 

 his colleague Prof. Milne-Edwards, by whom they 

 were described and named in a memoir cominuni- 

 cated to the second Ornithological Congress held at 

 Budapest in 1891. Almost at the same time the 

 present writer was engaged on a catalogue of the 

 fossil birds in the British Museum, and as this was 

 published a few months earlier than the report of 

 the congress, his names antedate those of his French 

 colleague. With these works as a starting-point. Dr. 

 Gaillard has for several years past been endeavouring 

 to amplify and consolidate our knowledge of the bird 

 fauna of the phosphorites, and the memoir now before 

 us is the result of his labours. Not only has a very 

 larg'e number of actual specimens passed throug-h his 

 hands, but he has obtained plaster-casts of the phos- 

 phorite bird-bones from almost all the museums in 

 Europe, thus enabling him to carry out his task in 

 a manner which would otherwise have been impos- 

 sible. 



Unfortunately, all the bird-remains from the French 

 phosphorites occur in the form of isolated and fre- 

 quently imperfect bones, so that it is in many cases 

 a matter of extreme difficulty to associate bones of 

 one part of the skeleton with species or genera passed 

 on those from another portion. In this matter the 

 author appears, however, to have been wonderfully 

 successful. 



As the result of his labours. Dr. Gaillard is enabled 

 to identify more than forty species of birds from 

 the phosphorites, which are referable to five-and- 

 twenty genera. Although these represent only a small 

 percentage of the bird-fauna of that epoch, they are 

 sufficient to indicate its extremely interesting char- 

 acter. The main interest is concentrated on two 

 points : — first, the indications of affinity between 

 groups now more or less widely sundered ; and, 

 secondly, the remarkable evidence of the mingling of 

 what are at present exclusively African with ex- 

 clusively South American types. It should be added 

 that, with very few exceptions, the genera are extinct. 



As regards the first point, it must suffice to men- 

 tion that the genus described as Strigogyps appears 

 to present structural resemblance to the owls, on the 

 one hand, and to the vultures (and the diurnal birds- 

 of-prey generally) on the other. 



In connection with the second point, it is most note- 

 NO. 2039, VOL. 79] 



worthy that while secretary-birds, sandgrouse, the 

 game-birds of the genus Palseocryptonj'x, and rollers 

 and turacos (Geranopterus and Dynamopterus) give 

 to the fauna a notably African and Indo-Malay 

 facies, on the other hand, a number of types, such 

 as Plesiocathartes (a relative of the condors), Ortho- 

 cnemus, Elaphrocnemus, Filholornis, and Archsetrogon 

 (which respectively resemble the chajas, the hoatzin, 

 the guans, and the trogons) present an equally 

 marked approximation to the modern avifauna of 

 South America. Such resemblances form one more 

 link in the chain connecting the Tertiary fauna of 

 Africa with that of South America, and the varied 

 materials of vi-hich the links in that chain are re- 

 spectively constructed render it difficult (despite the 

 persistent efforts that have been made to explain 

 away the force of the evidence) to give any satis- 

 factory explanation of the resemblance other than a 

 former land-connection between the two continents 

 across the Atlantic. For his labours Dr. Gaillard 

 merits the thanks of all naturalists. 



To an English ear the title of the second of the 

 two memoirs quoted at the head of this review scarcely 

 gives an adequate idea of its contents, as in this 

 country we are accustomed to restrict the term turtle 

 to the reptile so well known at City feasts and its 

 immediate relatives, whereas on the other side of the 

 .\tlantic it seems to be taken to include tortoises and 

 terrapins. In yet another respect this bulky quarto 

 volume is more than it seems, since it contains, in 

 addition to its proper subject, an excellent disserta- 

 tion on the structure, taxonomy, and distribution of 

 the Chelonia. In this respect it may be noticed that 

 the author adopts the suggestion made several years 

 ago bv the present writer as to Chelyidse (instead of 

 Chelydidae) being the proper form of the family name 

 derived from Chelys. 



The study of American fossil chelonians commenced 

 with Leidy in 185 1, since which date an almost con- 

 tinuous advance has been made, with a specially large 

 output of work during the last few years. In the 

 present volume no fewer than 266 species are recog- 

 nised, of which 76 are described for the first time. 

 The author has made a special point of endeavouring 

 to examine, whenever possible, the type-specimens of 

 each species ; in some cases these have, however, been 

 irretrievably lost, and in others mislaid. 



A special feature of American fossil Chelonia is the 

 number of species belonging to the group termed by 

 the present writer Amphichelydia, of which the typical 

 representative is the British Jurassic genus Pleuro- 

 sternum. In North America the group is very largely 

 represented by the allied family Bjenidae, which shows 

 greater specialisation in the structure of the vertebrae 

 of the neck and of the bony buttresses connecting 

 the lower with the upper shell. Another very char- 

 acteristic family of .'\merican chelonians is the Cre- 

 taceous Toxochelyidas. The author furnishes some in- 

 teresting suggestions with regard to the phylogeny of 

 the Chelonia, and likewise discusses their supposed 

 relationship to the Sauropterys'ia. 



Almost the only fault we have to find with the 

 volume is the absence of a good table of contents, or 



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