92 DEVONIAN FAUNA. 



ao"ed shell, which from its shape and the position of the matrix, is peculiarly diffi- 

 cult to delineate. The shell itself has a rather less curvature, and has a less rugged 

 appearance than is indicated in the drawing, and the interspaces of the longi- 

 tudinal ribs do not possess the five or six coarse bands which are there represented 

 between the main transverse ridges. It would indeed be almost impossible to 

 recognise the species from this figure, and it was only by a careful comparison 

 of the difierent specimens that I discovered that they all belonged to the same 

 shell. Indeed, for a long time I imagined the youngest and most perfect specimen 

 to be a distinct form ; and as such I described it in a paper read at the Bath meeting 

 of the British Association in 1888, taking for granted at that time the correctness 

 of Phillips's identification of his fossil with the Cyrtoceras ornatum of Groldfuss. 

 However, on comparing the English specimens of G. ornatum (Phill.) with the 

 German examples of G. ornatum (Groldf.)^ and G. Eifelense (d'Arch. and de Vern.)^ 

 in the British Museum in company with Mr. Foord, we came to the conclusion 

 that it was clearly distinct from both these shells. It is coiled elliptically instead 

 of in a circle ; it tapers much more rapidly than the former, and much less 

 rapidly than the latter ; its ornamentation is of a different character, and it is 

 much less symmetrical than either. It then occurred to me that the shell I had 

 described as G. prcedarum, although totally different from Goldfuss's shell, had 

 much the same character as these other English specimens, and ought probably to 

 be united with them ; and upon consulting Mr. Foord he confirmed my impression 

 of their identity. Its ornamentation is neater and more regular than that of the 

 others, but this is at once accounted for by its youth and its better state of 

 preservation. We also found that the two large and complete specimens in 

 Mr. Vicary's collection clearly belonged to the same species. Hence we have 

 arrived at the true shape of Phillips's shell, and this finally confirms its distinct- 

 ness from the German species, which are of a very difi'erent habit of growth. 



The question of its nomenclature next comes before us. Phillips and the 

 French authors both quote Goldfuss's MS. name. In this Phillips has the 

 priority, but his identification was formally uncertain, and was only made upon the 

 authority of de Verneuil, who had seen his fossil. It appears, therefore, that the 

 foreign authors must be considered to be the authoritative exponents of Goldfuss's 

 species, and that therefore either Phillips's MS. name G. foliaceum must be taken 

 for our species, or a new name sought for it. As, therefore, I have given a short 

 description of a shell of this species under the name of G. preclarum it seems 

 better to retain this than to sink it in order to revive a manuscript name which 

 Phillips had himself discarded. 



The change in the ornamentation with its growth is very great ; indeed, so much 



1 Manuscript name in Bonn Museum. 



- 1842, D'Arch and de Vern., ' Geol. Trans.,' ser 2, vol. vi, p. 349, pi. xxxi, figs. 2, 2 a, b. 



