This article was downloaded by: [JAMES COOK UNIVERSITY] On: 17 March 2015, At: 04:08 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Annals and Magazine of Natural History: Series 5 Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tnah11 I.—On the Genera Dipterus, Sedgw. & Murch., Palædaphus, Van Beneden and De Koninck, Holodus, Pander, and Cheirodus, M'Coy R.H. Traquair M.D. F.G.S. a a Museum of Science and Art , Edinburgh Published online: 15 Oct 2009. To cite this article: R.H. Traquair M.D. F.G.S. (1878) I.—On the Genera Dipterus, Sedgw. & Murch., Palædaphus, Van Beneden and De Koninck, Holodus, Pander, and Cheirodus, M'Coy , Annals and Magazine of Natural History: Series 5, 2:7, 1-17, DOI: 10.1080/00222937808682375 To link to this article: http://dx.doi.org/10.1080/00222937808682375 PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions Downloaded by [JAMES COOK UNIVERSITY] at 04:08 17 March 2015 THE ANNALS AND IAGAZINE OF NATURAL HISTORY, [FIFTH SERIES.] ~' .................. per litora spargi~e museum t Naiades, et circttm vitreos considite fontes: Pollice virgineo teneros hie carpite flores : :Floribus et pictmn, diva~, replete canistrum. At vos, o ~ymph~e Craterides, ire sub undas ; Ire, recurvato variata corailia trunco Vellite muscosis e rupibus, et mihi eoncha.e Ferte, nero pelagi, et pingui conehylia succo." iV. Parthenil Giannettasli EeL 1. No. 7. JULY 1878. I.--On the Genera Dipterus, Sedgw. & Murc£., Palmdaphus, Van Beneden and De KonlncIc, Holodus, Pander, and Chei- rodus, M~Coy. By R. H. TRAQUAIR, M.D., F.G.S., Keeper of the Natural-History Collections in the Museum of Science and Art, Edinburgh. [Plate III.] I. DIPTERIIS, Sedgwick and Murchison. The genus Dipterus of Sedgwick and Murchison was clas- sified by-Agassiz first in his family of L~pidoides*~ and after- wards in that of the Sauroides Diptdriens t, in which latter it was associated with such rhombic-scaled genera as Osteolepis~ 2)ijolopterus, and GlyptoTomus. In fact Agassiz himself be- lieved that the scales of D~terus were rhomboidal. The cycloidal shape and imbricating arrangement of its scales, however, were pointed out by M~Coy~;, who accordingly placed it among the ~' Ccelaeanthi" (i. e. cycliferous Crosso- Downloaded by [JAMES COOK UNIVERSITY] at 04:08 17 March 2015 pterygii according to modern ideas)~ and also doubted the propriety of separatin~ GlyptoleTis from it, although the very peculiar dentition of Dipterus had been already~ disco- vered by Hugh Miller§. But the incorrectness of M'Coy's ideas upon this latter point was immediately afterwards * ~Poissons Fossiles,' vol. ii. pt. 1~ pp. 3 and 112. t ~Poissons Fossiles du vieux Grbs Rouge~' pp. 47, 49~ and 58. ~British PalmozoicFossils/pp. 590-503. § ~Witness' Newspaper, Dec. 23, 1848; ~Footprints of the Greator~' Edinburgh, 1850. Ann. & J[ag. h~, If let. Ser. 5. Vol. ii. 1 2 Dr. R. It. Traquair on the Genus Dipterus. shown by Pander *~ who gave an excellent account of the structure of Dipterus~ and proposed to institute for it the new family of Ctenodipterini 7 a term afterwards altered by Sir Philip Grey-Egert-en into Cte~ododipterini t. This fa-mily~ in which Ceratodus :~ and Cheirodus were also provisionally included, was accepted by Prof, Huxley, and placed by him in his suborder Crossopterygidm §. ~3/Ioreoverr in a remark- able and oft-q~toted passage, he drew attention to the singular relations subsisting between the living Protojoterus and the cycliferous Crossopteryg~&e, especially as regards those of the latter which have acutely lobate paired fins. Though Prof. I-Iuxley did not class the Dipnoi as Ganoids, nor Dipterus as a Dipnoan, he struck the keynote to its real position in the sentence :--" Furthermore Lepidoslren is the only fish whose teeth are comparable in form and arrangement to those of Dipterus." . The discovery of Ceratodus Forsterl in the rivers of Queens- land, and its addition to the catalogue of living/)ipnoi, threw a fresh flood of light on the subject; and Dr. Gtinther was not Iong in following up the idea suggested in Prof. Huxley's remark quoted above. Guided chiefly by the obvious simi- larity in D iTterus and Ceratodus of the bones of the lower aspect of the skull and of the mandibl% the dentition, the want of distinct maxillary and pr,emaxitlary elements~ the position of the nasal apertures~ the notoehordal vertebral axis~ the acutely lobate condition of the paired fins~ and the eyeloidal seales~ Gtinther proposed to actually include the Ctenododipterini as a family of Dipnoi~ looking upon these Dipnoi, however, not as a distinct orcler of fishes, but merely as a "suborder" of the Ganoidei. On the other hand the leading differences between Dil)terus and Ceratodus, as indicated by Giinthe U may be summarized as follows :--the heterocercy of the former genus~ its dorsal fin. being divided into tw% the enamelled surface of its scales, the enamelled seutes of its cranial buckler~ its gular plates, the dermal rays of the median fins being joined to the extremities of the interneural and interhtemal spines: the latter Downloaded by [JAMES COOK UNIVERSITY] at 04:08 17 March 2015 being branched at their distal ends~ and~ finally, some unes- sential differences in the microscopic structure of the dental plates. Yet, "weighing the points of affinity and difference against each other," Dr. Gtinther observes~ "we must come * ~Ueber die Ctenodiptcrinen des devoniscJaen Systems~' St. t'eters- bm'g, 1858. t Dec. Geol. Survey, x. 1861, p. 55. :~ Beyrich had, indeed, previously noticed the resemblance between the dental plates of JDipterus and Ceratodus (~ Zeitsct~rift der deutscJaen geoloff. Gesellsch.' 1850, p. 154). § Dec. Geol. Survey, x. 1861. Dr. R. H. Traquair on rite Genus Dipterus. 3 to the conclusion that D~pterus has a better right to be asso- ciated with the living Dipnoi than with PolyTterus" ~. Prof. Huxley, however, in his recent and very valuable paper on Geratodus~ takes a different "view of the matter J'. In this paper Prof. Huxley performs the great service to science of pointing out that in their "autostylic " skull the Dipnoi differ essentially from the Ganoidei, which are "hyo- stylic ;" and in reference to Dr. Giinther's proposed classifica- tion he concludes "that it is better to retain tile Miillerian groups of Dipnoi (Sirenoidei, Mtiller), Ganoidei, Teleostei, Plagiostomi, and Chim~eroidei (Holocephali, Mtiller) as equi- valent and distinct natural assemblages." And as regards JOipterus, he seems to consider that its place is with the Ganoids, saying concerning it, "But even Dipterus,. which approaches Ceratodus and Le2idoslren so closely m its denti- tion and in the form of its fins, is far more similar to Poly- 2)terus and Amia in other respects ; and there is at present no reason to believe that any of the Crossopterygian Ganoids possessed other than a hyostyllc skull, or differed from Poly- Tterus in those respects in which lPolypterus differs from the existing Dipnoi. All known Crossopterygians have jugular plates, of which there is no trace in the Dipnoi. And as to the position of the anterior nares, which appear to have been situated on the under face of the broad snout~ not only in Dipterus, but in Osteolepis and Diplopterus, I have shown above that, so far from being a diagnostic character of the Dipnoi, it is simply an embryonic feature retained in them, the Selachians, and very probably in many of the earlier Ganoidei." In a recently published memoir on Ceratodus ~, Mr. L. C. Miall follows Dr. Gttnther in classifying Cera~oclus and Lepi- dosiren with the Ganoidei ; and as regards the special affinities of the Ctenododipterini~ the following statements made by him may be quoted :-- "~Te do not know for certain that Dijgterus and Ctenodus are hyostylic ; but the suggestion has a certain degree of pro- Downloaded by [JAMES COOK UNIVERSITY] at 04:08 17 March 2015 bability." But in a footnote appended to this passage he states, "The fossil suspensorium of DiTterus , marked xvi~, in the Museum of Practical Geology seems to show that this genus agrees with Ceratodus rather than with Pol!/pterus in the mode of suspension of the mandible ; but a fuller discus- "Description of Ceratodus," Phil. Trans. 1871. t Proc. Zool. Soc. London, 1876, p. 57. :~ "On the Genus Ceratodus~with special reference to the fossil teeth found at Maledi, Central India," Palmont. Ind. ser. iv. 2, Calcutta, 1878.