144 



SCIENCE. 



[Vol. XI. No. 268 



The four remaining chapters are devoted to the planets and the 

 moon, meteors, comets, and the stars. All equally interesting with 

 the opening chapters, they deserve equal mention, but space forbids. 

 Suffice it to say that they bring our information of new discoveries 

 in these interesting fields up to date; some beautiful reproductions 

 of the photographs of stellar spectra, taken at the Harvard College 

 Observatory, being among the latest important additions to our 

 knowledge of stellar constitution. 



In conclusion, we liope that this excellent work of Professor 

 Langley may go far towards its avowed object in arousing an inter- 

 est in the new, not versus, but to an equal degree of importance 

 with, the old astronomy. There can be no question that it is of as 

 much importance to mankind to-day to know wJiat the heavenly 

 bodies are, as where they are ; and the endowments to obtain 

 men and apparatus (the former more scarce, and the latter more 

 complicated and perhaps expensive) with which to answer the first 

 question should be forthcoming. In the report, some years ago, of 

 the National Academy of Sciences, upon the importance of moving 

 the National Observatory to a new site, the establishment of a 

 physical observatory under government auspices was recommended. 

 This is directly in the line of the purpose of this book, and we trust 

 that the latter may be one of the active factors in bringing into be- 

 ing, under government auspices, an observatory wherein the spec- 

 troscope, bolometer and galvanometer, polariscope, and photometer, 

 with the rapid photographic plate as the adjunct of all, may stand 

 on an equally important footing with the meridian-circle and the 

 equatorial with only filar-micrometer attached. 



NOTES AND NEWS. 

 The latest results of the work of Prof. Josiah P. Cooke and 

 Mr. T. W. Richards give as the atomic weight of oxygen, 15.869 ± 

 0.0017. This is from a paper presented at the American Academy 

 of Arts and Sciences March 14. 



— Hartleben's great atlas, ' Die Erde in Karten und Bildern.' is 

 now well advanced. So far, twenty numbers have been issued. 

 The maps are good lithographs, clearly drawn, well lettered, and 

 not overcrowded with names. They serve admirably the purpose 

 of the general reader. The accompanying text is profusely illus- 

 trated, and contains numerous views, costumes, etc. The physical 

 geography is now complete, and is followed by a succinct geography 

 of Europe. The price of the whole atlas is only $14.75. 



— In Science of March 9, p. 121, ist column, 29th line from bot- 

 tom, for ' 90 mm.' read ' 65 mm.' 



— In Science of Feb. 24, p. 96, ist column, last line, for ' 108 ' 

 read '118.' 



LETTERS TO THE EDITOR. 

 Unusual Dermal Ossifications. 



In examining the collection of Testiidinata in the Yale College 

 Museum, 1 found in specimens of Tesiudo Leithii, Giinth., dermal 

 ossifications, which, so far as I am aware, have never been de- 

 scribed. 



Each fore-limb of this small tortoise is furnished with a well- 

 ossified shield, which covers the anterior and inner part of the 

 limb. This shield is composed of suturally united ossicles, covered 

 by scales, and corresponding in number to the large scales on the 

 fore-arm. Each ossicle is smooth on the inner side, and elevated 

 into an eccentric tubercle on the outer side. 



This condition seems important for the explanation of the origin 

 of the carapace and plastron of the Testudinata, and supports my 

 view on ttiis point published elsewhere (Zool. Anzeiger, Nov. 22, 

 1886). 



There can be no doubt that this peculiar shield of the fore-foot 

 originally consisted of small, free ossicles. Probably different 

 stages of this condition will be found, if these parts are carefully 

 examined in the TcsUidi7iidce. 



The elemental form of the carapace was, there seems to be little 

 doubt, exactly the same. There appeared at first distinct ossicles 

 in the skin. With further development in this direction, these 

 ossifications touched each other, forming a closed shield, the single 

 elements o f which were connected by suture. 



As soon as this shield became connected with the endoskeleton- 

 it found a support, many of the sutures disappeared, and the ele- 

 ments of the shield were disposed according to the arrangement 

 of the endoskeleton. 



In the above way the costal plates were developed. The ossicles, 

 finding a support on the ribs, co-ossified with them and with each 

 other. 



The plastron has developed in the same way. The basis of the 

 plastron probably consisted of dermal ossifications, generally called 

 ' abdominal ribs.' By the increase of these dermal ossifications, the 

 'abdominal ribs,' the clavicles, and interclavicle were absorbed, 

 forming a solid shield, in which the clavicles and interclavicle were 

 transformed into epiplastron and endoplastron. 



The oldest condition of the plastron of the Testudinata, therefore, 

 was solid, and not pierced by fontanelles. 



The oldest known representative of the Testudinata, Trogano- 

 cJielys (G. Baur. ' Ueber den Ursprung der Extremitiiten der 

 Ichthyopterygia,' in Bericht iiber die xx. J^ers. des Oberrhein. 

 Geol. Vereins, Stuttgart, 1887, pp. 17, 18), from the triassic of 

 Wiirttemberg, confirms this opinion. 



Embryology has nothing to say in this regard. The whole 

 plastron (with exception, perhaps, of the epiplastron) is of dermal 

 origin, and has nothing to do with the endoskeleton ; but the 

 ontogenesis of the exoskeleton is of no value for phylogenesis. 



There are many authors (especially Cope and Dollo) who think 

 that the representatives of the Dermochelydidce {Sphargididai), 

 Dennochelys de BI. and PsephopJiorus v. Meyer, are original forms ; 

 and Cope has created a peculiar group, ' Atltecce,' for these and 

 some allied genera {Protostega, Cope ; Protosphargis, Cap.). 



I cannot agree with this opinion, but consider these forms as the 

 most specialized of the sea-turtles. 



One group has developed from a form of Testudinata with well- 

 developed carapace and plastron, by dissolution of their elements, 

 into single ossicles, connected by suture (^Dennochelys, Pseplto- 

 phorus). The other group has developed from a form of Testudi- 

 nata by rudimentation cf the costal plates {Protostega, Proto- 

 sphargis). 



The enormous Chelonia Hqffmanni, Gray, which has the costal 

 plates very little developed, and the marginals very slender, shows 

 characters between the Cheloniidce and Protostegidce, especially 

 Protosphargis, and must rank as a different genus, which I propose 

 to call ' Allopleuron ' (the generic characters are, costal plates, even 

 in the adult, very little developed, covering only one-half of the rib ; 

 marginals very slender). 



There have never been found mosaic-like dermal ossifications, 

 neither in Protostega nor in Protosphargis. The plates considered 

 by Professor Cope as probably belonging to the carapace belong to 

 the plastron. The marginals have not disappeared, as in the Der- 

 mochelydidce, but are present ; those of Protosphargis, described by 

 Capellini as probably phalangeal bones, resemble very much these 

 elements in Allopleuron. 



Sea-turtles have probably been developed at different times and 

 in different localities, in the same way as the gigantic tortoises. 

 The species of the Galapagos Islands are not directly related to 

 those of the islands round Madagascar. Both have originated 

 from two different stocks, — the first from some form of the 

 American continent, the second from some one of African type. 



G. B.A.UR. 

 New Haven, Conn., March 4. 



End of the Swindler. 



It will give undoubted satisfaction to his many victims to learn 

 that the ' swindling geologist,' whose depredations have been so 

 frequently noted in your columns, has been lately convicted of steal- 

 ing a number of microscopic objectives from the University of Cin- 

 cinnati, and sentenced to spend five years at hard labor in the Ohio 

 Penitentiary. He was sentenced under the name of O. L. Syrski, 

 but admitted having pursued his calling under a variety of aliases, 

 such as Taggart, Vasile, Ellison, Cameron, Douglas, Strong, Lee, 

 Arundal, and Lesquereux. A valuable microscopic objective, 

 found in his possession, awaits identification by the owner. 



Chas. H. Gilbert. 



Cincinnati, March 9. 



