GONIATITES. 69 



Affinities. — G. Noeggerathi, von Buch, as given by d'Arcliiac and de Verneuil,^ 

 presents a similar superficial appearance, but its back is narrower, and shows no 

 signs of a keel, and its lobes are described as being more complicated. 



G. globosus var. Nehdensis, Kayser,^ is distinguished by the nodulated margin 

 of its umbilicus. 



Ammonities lateseptatus, Beyr.,^ has a much larger umbilicus, no lateral lobes ; 

 and is a much larger shell. F. A. Romer* bears out the points in Beyrich's 

 description, which, distinguish it from our shell. 



G. plebeius, Barrande,^ has a more open umbilicus and no lateral lobe in the 

 suture-line. It is regarded by Kayser® as a synonym of G. lateseptatus, Beyrich. 



G. plebeifornds, Hall,'^ differs from ours in the same direction as, and to a greater 

 degree than, does the last-named Bohemian species. 



8. GoNiATiTES Hdghesii, WMcUome. Plate VI, figs. 1 — 3. 



1889. GoNiATiTEs HxjGHESii, Whidb. Greol. Mag., dec. 3, vol. vi, p. 29. 



Description. — Shell large, flattened, involute, slightly elliptic. Umbilicus 

 closed by the upper whorl, but apparently existing, though minute, in the whorls 

 below. Mouth somewhat expanding laterally, thickened near the umbilicus. 

 Sides of the whorls gently rising just around the umbilicus, but soon after sinking, 

 with a very slight convexity, to the ventral area, where they curve rapidly over 

 the rounded back. Suture-line rising perpendicularly from the umbilicus, and 

 going forward in a wide concave saddle over about two-thirds of the length of 

 the whorl, when it forms a long, narrow, rounded lobe, and then bends sharply 

 back in a steeper central saddle ; central portion forming a narrow, elongate, 

 central lobe. Surface covered with a microscopic and curious pattern of oblique 

 and close discontinuous lines curving backwards from the dorsal margins much 

 more obliquely than the suture-lines. 



Size. — 90 mm. in height, 65 mm. in width, 24 mm. in depth. 



Locality. — Lummaton. There are two specimens in my collection, two others, 



• 184i2, D'Arch. and de Vern., ' Geol. Trans.,' ser. 2, vol. vi, pt. 2, p. 337, pi. xxv, figs. 1, la, b. 

 2 1873, Kayser, ' Zeitsclir. deutsch. geol. Gesell.,' vol. xxv, p. 625, pi. xix, fig. 4. 



^ 1837, Beyrich, ' Beitr. Ebein. Ubergangsg.,' p. 25, pi. i, figs. 1—4, and 1887, Freeh, 'Zeitsch. 

 deutsch. geol. Gesell.,' p. 732. pi. xxvii, figs. 12, 12 a. 



* 1860, F. A. Rom., 'Beitr.,' pt. 4, p. 157, pi. xxiv, figs. 2a, b, c. 



5 1865, Barrande, ' Syst. Sil. Bohem.,' vol. ii, p. 37, pi. v, figs. 1 — 25 ; pi. vi, figs. 1 — 5; pi. vii, 

 figs. 3—9, Et. F and G. 



'^ 1878, Kayser, * Abhandl. Geol. Specialk. Preussen,' Band 2, pt. 4, p. 50, pi. vi, figs. 1—7. 

 7 1879, Hall, ' Pal. N. T.,' vol. v, ser. 2, p. 448, pi. xvi, figs. 25, 26; and pi. ex, figs. 3—9. 



