THE 



GEOLOGICAL MAGAZINE 



NEW SERIES. DECADE III. VOL. IX. 



No. I.— JANUARY, 1892. 



Oi^I(3-IITJ^IJ J^I2,TiaLES. 



1. — On the Lower Devonian Fish-Fauna of Campbbllton, New 



Brunswick. 



By Arthur Smith Woodward, F.L.S., F.G.S. 



(PLATE I.) 



THE Lower Devonian Fish-Fauna of Campbellton, New Brunswick, 

 has already been described by Mr. Wliiteaves,' of the Canadian 

 Geological Survey, and Dr. Traquair,* of Edinburgh; and a few 

 supplementary observations are published in the British Museum 

 Catalogue of Fossil Fishes, Part II. (1891). Much, however, still 

 remains to be learned concerning the skeletal anatomy of the genera 

 and species already determined ; and many types of early fishes will 

 doubtless soon be discovered by future explorers of the formation 

 and locality in question. A new series of specimens just received 

 by the British Museum from Mr. K. F. Damon, of Weymouth, adds 

 some small items of interest to our knowledge of the subject ; and 

 the following notes relate to the advance thus made. The fossils 

 under discussion were collected last summer by Mr. Jex, and are 

 all much crushed and flattened in the usual manner. 



ELASMOBRANCTIIL 

 Genus Protodus, no v. 



A genus known only by detached teeth. Dental crown consisting 

 of a single robust, solid, conical cusp, invested with gano-dentine ; 

 root large, undivided, laterally expanded, and antero-posteriorly 

 compressed. 



That the tooth thus defined is not the laniary of a Crossopterygian 

 attached to its basal bone is proved by the examination of a micro- 

 scopical section, which leaves little doubt as to its Elasmobranch 

 relationships. Protodus is thus the earliest tooth referable to the 

 Elasmobranchii hitherto determined, and is especially remarkable 

 on account of the form of the root. There is much reason to believe 

 that all the more primitive Elasmobranch teeth possess a horizontally 

 expanded base (or root), while antero-posterior compression is the 



1 J. F. "Whiteaves, Canadian Naturalist, n.s. vol. x. (1881), pp. 93-100 ; also 

 " Illustrations of the Fossil Fishes of the Devonian Eocks of Canada, Part II.," 

 Trans, fioy. Soc. Canada, vol. vi. sect. iv. (1889), pp. 92-96, pi. ix. pi. x. figs. 2-4. 



* R. H. Traquair, "Notes on the Devonian Fishes of Scauraenac Bay and 

 Campbelltown in Canada," Geol. Mag. [3] Vol. VII. (1890), pp. 20-22 ; 

 also " On Phlyctcenius, a New Genus of Coccosteidae," ibid. pp. 55-60, pi- iii. 



decade III. VOL. IX. NO. I. 1 



