( 332 ) 

 The dorsal vertebrae have the following measnrements ; 



The nnmber oi cnathd rprtchnte is 2T iu the midi', and ^!0 in tXxe femnle. 



^^ ith regard to the attachment nf the iliac bones X\\e femiih' specimen differs 

 frnm the two males. In the latter the iliac hones abnt against the plenrajiojihyses 

 of the tenth, eleventh, and twelfth vertebrae, the protuberance for the articulation 

 being opposite to the plenra])ophysis of the tenth vcrtelira. In the snuiller /('//('//c 

 the jdenrapojihyses of the ninth and tenth form the articulary tubercle, the eighth 

 joining it by anchylosis, and the eleventh (which is rather stout) and twelfth (which 

 is a very slender rod) by cartilage. Of course this is not to be regarded in the 

 light of a sexual character, but merely as an individual variation. 



In the foregoing notes I have paid particular attention to a comparison of 

 the material before me with T. ubim/donii, not only because the two sjiecies are 

 outwardly very similar, but also because Dr. Baur, in a ])aper published some 

 years before his visit to the Galapagos," maintained that T. abingdonii and 

 T. ephippi'im were the same species. He took this view for two reasons. 



I. Dr. Baur's first argument refers to the history of the type of T. 

 ephippiiim. 



In my first description of this ty]iet I had stated that "nothing is known 

 of its history " % ; but considering Porter's notice of the peculiar saddle-shaped 

 carajiace of the Charles Island tortoise applicable to the type of T. ephippium, 

 I suggested that this latter might have come from that island. Two years later 

 I abandoned this view, and thought Indefatigable Island more likely to be the 

 true habitat of this race.§ 



However, iu the ]>aper quoted above {.\mer. Sat. 188'.), ]). lir.i'.)), Dr. Baur 

 informs us of a very interesting discovery whicli ilcserves our fullest attention. 



• Amei: Nat. 1889, December, p. 1039. 



t Philog. Tiatu. l.r. 



% I believe this statement was fully justified on my part. To a letter which I addressed in 1872 

 to the then Director of the Museum of Science and .\rt, asking for information .ibout the history of 

 the specimen, I received the following reply : — 



" EDlNltUltUH, Ml'tJEUM Ot SCIENCE ASI) .\BT. 



" Maieh Sill, 1872. 

 '• DE.\R Db. tiLXTHER,— 



" Mr. Archer having handed me your letter about the tortoises, I am sorry to say we have no 

 record of it.'i history witli which we can assist you in your work. It belongs to the i)rehistoric period 

 of our museum ! 



" Yours ever faithfully, 



" (si/.) Ramsay H. Traqcair." 



Two years later I made another attempt, and requested my late friend, Dr. Alexander Smith of 

 Edinburgh, to make further inquiries into the matter ; but he also, under date of February Hith, 1874, 

 wrote to me that he had been unsuccef.sful in finding out anything about the histoiy of the 

 specimen. 



^ Gigant. Laml Tort., p. 11 (1877). It is unfortunate that in republishing in 1S77 my first 

 description of 1874, I omitted to alter the p.issage treating of the probable habitat of this species, and 

 to state the rea.son8 by which I was induced to change my opinion. 



