April. 28. 1887] 



NA TURE 



617 



the tail is enveloped in a continuous sheath. These and other 

 scale-like structures in the Chelonia are usually spoken of as if 

 they were entirely epidermal. But, a day or two ago, Dr. 

 GUnther informed me that in the Australian tortoise, Manouria, 

 the great imbricated scales of the limbs contain bony scutes ; 

 and that similar scutes are to be found in Tisttuio gncca. This, 

 of course, suggested the examination of the caudal scales of 

 CluiyJra and Gypochclys ; and, having been enabled by Dr. 

 Giinther's kindness to e.xamine the caudal scales of a good-sized 

 specimen of the latter, I have found that those of the crest con- 

 tain bony scutes.' The bony scute corresponds very closely in 

 form with the whole " scale," but the recurved apex of the latter 

 is formed only by epidermal substance (Figs. 5 .and 6). 



JVS 



Figs. 5. 6. — Sectional views of a scute of the tail-armour o( Ccfaiochflys 

 (Fig. 5). and of one of the crest plates ai Gypochclys, both of the natural size. 



The living Chelydra, therefore, has a caudal armature which, 

 in principle, is similar to that of Ccnitochelys, but the osseous 

 elements are relatively atrophied. There is exactly the same 

 relation between the armour of species of living Crocodile! and 

 Alligators, on the one hand, and those of Jacare and Caiman 

 and the extinct Telcosauria, on the other. In the former, the 

 epidermal scales remain well developed on the ventral side of the 

 body, while the corresponding osseous scutes, fully developed in 

 yacarc. Caiman, and Telcosauria, have vanished. 



AiTiong the detached fragments to which I have referred, there 

 are remains of ribs, with their costal plates ; marginal and other 

 plates of the carapace ; parts of the plastron ; part of a scapula ; 

 -undry limb bones ; and several of the cranial processes called 

 "horn-cores." They all agree, so far .as they can be com- 

 pared, with the determination already arrived at ; which, to sum 

 it up in a few words, is that the remains of crania and caudal 

 sheaths from Australia, hitherto referred to Saurian reptiles, 

 under the names of Mcgalaiiia and Mciolania, appertain to a 

 hitherto unknown species of Chelonian, Ceratochclys stheniiriis, 

 closely allied to the living Chelydra, Gyfoche'ys, and Ptaty- 

 slernum. 



The evidence of this fact offered in the present note appears 

 to me to be conclusive, but it may be desirable hereafter to figure 

 the parts mentioned and to describe them at length. 



The intere.t which attaches to the discovery of this singular 

 Chelonian arises partly from the fact that the group of Chelonia 

 to which it belongs is wholly unrepresented in the fauna of 

 Australia, .as at present known. Platyslcrnum is usually said to 

 be found in China. Dr. GUnther, however, informs me that 

 Upper Burmah is its proper habitat ; otherwise. North America, 

 east of the Rocky Mountains, is the nearest region in which the 

 Chelydridcc are to be found. But Chclydrlda, and, indeed, 

 species of the genus Chelydra, occur in Upper Miocene (CEnin- 

 gen) and in Eocene formations in Europe. Moreover, Platy- 

 c/ielys, of the Upper Jurassic series of Bavaria and .Switzerland, 

 is regarded by Rutimeyer as an early form of the group. 



Lord Howe's Island is about 200 miles from the nearest 

 -Australian mainland, and something like 400 miles, as the crow 

 tlies, from the Darling Downs, in which the caudal armour, 

 which has been ascribed to Afcgalania, was found. The dis- 

 covery of Ccrclochclys, therefore, has an interesting bearing on 



* The fact is noted by Rutimeyer (Lan? and Rutimeyer. " Die Fossilen 

 Schildkroien von Solothurn," Dcniischriften der Allg. Sclfwciz. Gesell- 

 schaft, vol. xxii. ). The armature of the tail in Platystemum is for the most 

 part arranged in zones, of four plates in each zone ; but I have not yet been 

 able to find any bone in them. 



the question of the former extension of Australia to the east 

 ward, on the one hand ; and of the possible derivation of such 

 forms as Ceratochclys from Asia, on the other hand. An eleva- 

 tion of the sea-bottom of 6000 feet would place Norfolk Island 

 and Lord Howe's Island on a peninsula extending from the 

 region of the present Barrier Reef to New Zealand ; and the 

 florre and fauna; of those islands are known to have special 

 affinities with those of New Zealand, and none with those of 

 Australia. 



Speculations respecting the origin of the Chelonian carapace 

 are suggested by the discovery of osseous scutes in the vertebral 

 region of the tail, and their coalescence in Ceralochelys to form 

 a sort of caudal carapace, ridged in a manner resembling that of 

 Chelydra and Platychelys. But the consideration of these points 

 would take me beyond the limits of the present note. 



THE WORK OF THE IMPERIAL INSTITUTE i 

 I. 



nPHE Colonial and Indian Exhibition, which owes not only its 

 "'• conception, but also its brilliantly successful realisation to 

 your Royal Highness, will be pre-eminently remarkable in times 

 to come, for having achieved many results of vital importance 

 and highest benefit to Her Majesty's subjects in all parts of her 

 vast realms. 



The collection of all that is commercially valuable and scien- 

 tifically interesting of the natural products of the great Indian 

 Empire and of the Colonies in one Exhibition, embracing as it 

 also did very comprehensive illustrations of the development of 

 commerce, of the arts, and of certain industries, in the many 

 countries beyond the seas which combine with the United 

 Kingdom to constitute our vast Empire, afforded those at home 

 an opportunity, surpassing all previous conception, of studying 

 and comparing the natural history and resources of those distant 

 lands, of which, attached though we might be individually to one 

 or more of them by ties of friendship or of interest, the know- 

 ledge of many of us was of a very vague or partial character. 



To the Colonists who visited us last year, the Exhibition has 

 been of inestimable value, in afl'ording them a most favourable 

 and appropriate opportunity of becoming acquainted or renewing 

 their old friendship with the mother country, and of examining 

 the progress there made in industrial, educational, and com- 

 mercial development ; in leading to the cultivation of intimacy 

 between Colonists from difi'erent sections of the Queen's 

 Dominions ; and in affording them invaluable opportunities of 

 comparing the resources and state of development of their 

 respective countries with those of other parts of Europe. No 

 more convincing illustrations than were provided by this great 

 Exhibition could have been conceived of the importance to the 

 home country, to each Colony, and to India, of fostering intimate 

 relationship and unity of action. No more encouraging proof 

 could have been afl'orded of the desire of all classes of Her 

 Majesty's subjects at home to cultivate a knowledge of those 

 far-off countries which the enterprise and perseverance of the 

 British, and men of British offspring, have converted into 

 prosperous and important dominions, chiefly during the period 

 of the Queen's reign, than was furnished by the interest which 

 the thousands upon thousands, who came from all parts, dis- 

 played in the study of the instructive collections in the galleries 

 at .South Kensington. 



It was the success of the Exhibition which led to the definite 

 formulation of the suggestion first made by your Royal Highness 

 in a letter addressed by you in the autumn of 1884 to the Agents- 

 General of the Colonial Government--, that a permanent 

 representation of the resources of the Colonies and India, and 

 of their continually progressing development, might, with great 

 benefit to the Empire at large, be established in this country. 

 That the realisation of this idea upon a sufficiently comprehen- 

 sive basis might constitute a worthy memorial of the 

 accomplishment of fifty years of a wise and prosperous reign ; a 

 memorial not personal in its character excepting so far as it con- 

 stituted an emblem of the love and loyalty of Her Majesty's 

 subjects, but tending, as she would most desire, to serve the 

 interests of the entire Empire; this had only to be pointed out 

 by your Royal Highness to be heartily concurred in by the 

 official representatives of the Colonies and India, who 



^ Lecture (abridged) delivered at the Royal Institution, on Friday, 

 Apr.l 22, by Sir Frederick Abel. C.B., F.R.S.; H.R.H. the Prince of 

 Wales, K.G., F.R.S., Vice-Patron, in the Chair- 



