THE 



GEOLOGICAL MAGAZINE. 



NEW SERIES. DECADE V. VOL. VIM. 



No. XL— NOVEMBER, 1911. 



ORIGIIT-A.L ARTICLES. 



I. — Upper Cretaceous Terebelloids from England. 1 



By Dr. F. A. Bather, M.A., F.E.S., F.G.S., etc. 



(PLATE XXIV.) 



IN April, 1879, William Davies published in the Geological 

 Magazine (n.s., Dec. II, Vol. VI, pp. 145-8) a paper on " Some 

 Fish Exuviae from the Chalk, generally referred to Bercetis elongatus, 

 Ag. ; and on a new species of Eossil Annelide, Terebella Lewesiensis". 

 Herein he discussed certain longitudinal or tubular agglomerations of 

 fish-debris, originally named Murcena{J) Leivesiensis, by G. A. Mantell, 

 but subsequently assigned by L. Agassiz to the fish described by him 

 as Bercetis elovgaius. References to the various papers and books in 

 which these remains had been mentioned will be found in the paper 

 quoted. From his profound knowledge of fossil fish Davies was able 

 to show that these agglomerations contained the remains of more than 

 one species of fish, and he considered that the fragments had been 

 collected and affixed to their tubes by annelids allied to the modern 

 Terebella. It is well known that some living species of that genus 

 have similar tube-building habits, so that the suggestion made by 

 Davies has been generally accepted, and the specimens in the British 

 Museum on which he based his conclusions have since then been 

 labelled Terebella (?) Lewesiensis Mantell sp. 



The object of the present note is to make known some slight 

 additions to our knowledge, and to discuss one or two points in the 

 paper by Davies. 



The specimens described by Mantell and Agassiz and the majority 

 of those studied by Davies were composed of the debris of fish. 

 In these specimens Davies pointed out diverse individual variations : 

 some are of small scales, with few or no bones [B.M. 25875, 25876] ; 

 others of large or small scales associated with numerous small bones 

 [B.M. 58259] ; others, again, have assembled long fin-rays "arranged 

 fairly in the direction of the long axis of the specimen", e.g. that 

 figured in Dixon's Geology of Sussex, pi. xxxiv, fig. 5 [B.M. 25942], 

 and the specimen 14 inches long, to which Davies specially referred 

 [B.M. 58261]. The variation, however, is considerably more than 

 this, for we now know of specimens from the Cretaceous rocks of 

 England that have a tube of quite other composition. One specimen 

 [B.M. A 1583], from the Cenomanian Grey Chalk of Folkestone, 



1 Published by permission of the Trustees of tbe British Museum. 

 DECADE V. — VOL. VIII. — NO. XI. 31 



