ARIETITES BUCKLANDI. 



269 



extremely ramified in Amaltheus, and the siphonal lobe is shorter than the principal 

 lateral lobe, which is mostly broad and wedge-shaped. These characters form a good 

 diagnosis for this genus. 



The Anapfychus is, thin, horny and undivided ; in some species it is bell-shaped. 

 I have found Anaptychi in the body-chamber of Arietites stellaris, Sow., and of 

 Arietites semicostatus. Young and Bird, where it exhibited these characters. 



The distribution of this genus is limited to the Lower Lias ; and its various species 

 characterise the different zones of life in which they are found, a fact which was 

 well known to, and clearly pointed out by, Leopold von Buch, in his classical memoir, 

 " Ueber die Ammoniten in den alteren Gebirgs-Schichten " (1830). 



Ammonites bisulcata, 



— bccklandi, 



— AKIETES, 



Planites bisulcatus. 

 Ammonites Bucklandi, 



Arietites Bucklandi, Sowerby. PI. I, figs. 1 — 3. 



Ammonis cornu, Lister. Animal. Angliee, tab. vi, fig. 1, p. 207, 1678. 



— — STRIATUM STRiis iNTEGKis (pars), ianp'. Historia Lap. fig. Helvetia, 



tab. xxiv, fig. 1, p. 95, 1708. 

 Bruguiere. Encyclop^die Methodique, torn, i, p. ,39, 1792. 

 Sowerby. Min. Conch., vol. ii, p. 69, tab. cxxx, 1816. 

 Schlotheim. Petrefactenkunde, p. 62, No. 4, 1820. 

 de Haan. Monogr. Ammonit. et Goniatit., p. 91, 1825. 

 von. Buch. Physik. Abhandl. Akad. Berlin, iiber Ammo- 

 niten, p. 142, tab. iii, fig. 1, 1832 (read 1830). 

 Zieten. Verstein. Wiirttemb., p. 35, tab. xxvii, fig. I, 1830. 

 Beshayes. Coquilles charac. des Terrains, p. 240, pi. x, 



fig. 2, 1831. 

 Bronn. Lethaea Geognostica, i, p. 421, tab. 22, fig. 1, 1833. 

 Mandelsloh. Constit. Geogn. Alp. Wiirttemberg., fig. 33, 



1835. 

 Homer. Norddeutsch. Oolitben-Gebirg., p. 182, 1836. 

 BucUand. Geol. and Min., ii, p. 59, tab. 37. fig. 6, 1836. 

 Quenstedt. Flozgebirge Wiirttemberg., p. 131, 1843. 

 Simpson. Monogr. of Lias Ammonites, Yorkshire, p. 52, 



1843. 

 Quenstedt. Petref. Deutsch. Cephalopoden, p. 76, 1846. 

 Quenstedt. Handbuch der Petrefactenkunde, p. 354, 



1852. 

 Ckapuis et Dewalque. Terr. Second, de Luxembourg, p. 42, 



pi. V, fig. 3, 1853. 

 Studer. Geologie der Schweiz, Band ii, p. 234, 1853. 

 Simpson. Monogr. of Yorkshire Fossils, Yorkshire, p. 97, 



1855. 

 Oppel. Die Juraformation, p. 76, 1856. 

 Quenstedt. Der Jura, p. 67, pi. vii, fig. 3, 1858. 

 Dumortier. Depots Jurassiques du Bassin du Rhone, torn, 



ii, p. 19, 1867. 

 Tate Sf Blake. Yorkshire Lias, p. 283, pi. v, fig. 2, 1876. 



— BISULCATUS 



— Bucklandi, 



Arietites — 



