GONIATITES. 67 



fourths the width of the whorl, and then bent sharply back, so as to form a deep 

 tongue upon the back. 



Size. — 26 mm. in height, 21 mm. in width, 10 mm. in length. 



Locality. — Barton. Two specimens in the Lee Collection in the British 

 Museum. 



Remarks. — This shell is in general form more like G. molarius than any of the 

 other accompanying species, differing, however, therefrom in the slope of its sides, 

 and the greater convexity of its back as well as in the presence of its remarkable 

 sulci, and the slight depression of the sides just beyond the margin of the 

 umbilicus. My examination of it, both when it was in Mr, Lee's Collection at 

 Villa Syracusa, and since it has found a lodgment in the British Museum, has led 

 me to regard it as certainly not belonging to that species. To no other shell 

 given by either Sandberger, Romer, or Phillips in their quoted works is it at all 

 similar. 



Goniatites subsulcatus, Miinster,^ presents a rather curious mimicry. The 

 suture-lines in that species (as seen in the side view) are similar to the sulci in 

 this, but its sulci themselves are straight and its umbilicus is minute. It is clearly 

 a totally different shell. 



Kayser's interpretation of ' Goniatites retrorsus, Sandb., var. Brilonensis 

 (Beyr.),'^ however, comes very near it, and chiefly differs in the umbilicus being 

 smaller and the sulci being less angulated, and being five instead of four. 



Ammonites diadema, Goldf., as figured by Beyrich,^ and G. Oweni, Hall,* are not 

 very dissimilar in general shape, but their sulci are straight instead of angulated, 

 and they are rather deeper shells. 



In G. truncatus, Phillips, as given by F. A. Romer,^ the sulci are direct and 

 almost straight. 



7. Goniatites globosus, Miinster ? PI. V, figs. 12, 12 a, 12 &, and PI. VI, figs. 5, 5 a. 



1832. Goniatites globosus, Mimst. tJber Clym. uad &on. Fichtelgeb., p. 16, 



pi. iv A, fig. 4. 

 1841. — — Fhil. Pal. Foss., p. 120, pi. 1, fig. 231. 



1851. — RETROBSUS UMBiLiCATUS, Sandberger. Verst. Rhein. Nassau, 



p. 107, pi. X, fig. 1, and pi. x a, figs. 11 — 13. 



1 1832, Munst., ' Uber Clym. und Gon. Ficlitelgeb.,' p. 17, pi. v a, fig. 2. 



2 1872, Kayser, ' Zeitsch. deut. geol. Gesell.,' vol. xxiv, p. 664, pi. xxv, fig. 2. 



3 1837, Beyricb, ' Beitr. Verst. Ehein. Ubergangsg.,' pt. 1, p. 41, pi. ii, figs. 8—10. 



* 1860, Hall, ' Thirteenth Rep. N. Y.,' p. 100, figs. 11, 12 ; and 1879, ' Pal. N. Y.,' p. 470, pi. Ixxiii, 

 figs. 3 — 8, and pi. Ixxiv, fig. 9. 



» 1852, F. A. Rom., ' Beitr.,' pt. 2, p. 94, pi. xiii, figs. 30 a, b, c. 



