Bihh'ographical Notices. 453 



_ This discovery again shortens the gap between the Chelo- 

 nians and the typical Reptilia. The group to which Hy- 

 draspis belongs is characterized by distinct nasals, separate 

 dentary bones, and strong transverse processes to the cervical 

 vertebrte, and is in those respects altogether of a more gene- 

 ralized type than the other Testudinata ; however, as regards 

 the shell and pelvis it stands apparently a step in advance, 

 and the Pleurodira have for that reason been regarded, per- 

 haps erroneously, as the most specialized type. Geologically, 

 so far as the record goes and if Dr. Baur's recent views on 

 certain Triassic Chelonians be correct, they are the oldest. 

 The Wealden Peltochelys Duchasteliij the type specimen of 

 which I was permitted to examine by my friend M. DoUo, is 

 unquestionably closely related to Hydraspis and Ghelodina. 

 I have a suspicion that it will prove to be the young of 

 Pleswchelys. 



It is undeniable that all the discoveries that have been 

 made of late give support to the view first expressed by Cope, 

 nearly twenty years ago^ on the affinities of those two groups, 

 the Chelonia and the Rhynchocephalia^ the systematic position 

 of which has given rise to so much controversy. 



BIBLIOGRAPHICAL NOTICES. 



A Texthoolc of Biology. By J. E. Ai^^swoeth Davis. 

 London: Charles Griffin & Co., 1888. 



Me. Davis has designed this textbook in order to meet the require- 

 ments of the Intermediate Science and Preliminary Scientific Exami- 

 nations of the Loudon University. Such a work can never be one 

 of a high class, for it must be limited by the conditions of the 

 syllabus of a given body ; in this case the body is not a teaching, 

 but only an examining one. 



Mr. Davis's book must therefore be tested solely by the syllabus 

 to which it professes to afford an aid. The exposition of the simple 

 facts of anatomy and physiology is generally accurate, but we do not 

 think it is better done than in a number of other works, such as 

 those of Huxley and Martin, or Marshall and Hurst. So far as the 

 work is, as it claims to be, an introduction to theoretical biology, 

 it is clear from the conditions imposed that it must be more or less 

 unsatisfactory in correspondence with the powers and characteristics 

 of the writer. For us the whole has too much the air of a cram- 

 book to justify us in recommending it from this point of view ; we 

 believe that the following explanation is the worst in the book, but 

 the mental calibre of the writer may perhaps be judged from it. 

 We find in the glossary, " Apodemo {u-n6h]i.ios, absent from home), 

 in the Crayfish. — One of the elements of the cndophragmal system." 

 Mr. Davis not only should have learnt that in Greek there is e and jj, 

 but he should have learnt too that explanations should explain 

 before he set to work on a glossary. The figures are partly original 



Ann. & Mag. N. Hist Ser. 6. Vol i, 31 



