428 THE LIAS AMMONITES. 



the Upper Lias at Whitby and Boulby, in Yorkshire ; Lyme Regis, Dorsetshire ;. 

 Dumbleton and Alderton, Gloucestershire. The Whitby specimens are by far the most 

 beautiful and best preserved. 



Foreign Distribution. — In France it has been collected at Eontaine-Etoupe-Four,. 

 Croiselle, Calvados; Charolles, Saone-et-Loire ; Thouars, Deux-Sevres ; CheviUe, Sarthe ; 

 Avallon, Yonne; Semur, Cote-d'Or ; Mende, Lozere; Verpilliere, Isere; Saint-Rambert,, 

 Ain ; Gundershoffen, Haut-Rhin. 



Luxembourg. — In the Marnes de Grande Cour. 



In Germany. — In the Posidonomyen-schiefer of Altdorf, Bavaria, Boll, and. 

 Wiirttemberg. 



Phylloceras stjbcarinatum, Young and Bird. PI. LXXXI, figs. 1, 2, 3. 



Nautilus subcauinatus, Young and Bird. Geol. York. Coast, p. 255, pi. xiir 



fig. 7, 1822. 



Ammonites — Phillips. Geol. of Yorkshire, p.l67, pi. xiii, fig. 3, 1835- 



— — Simpson. Monogr. on Ammonites, p. 8, 1843. 



— — Morris. Catalogue of British Fossils, p. 145, 1843. 



— — Co^mZ/o. Ammonit.delle Alps. Venete, pi. 13, fig. 3, 1846. 



— — Bronn. Index Palseontologicus, p. 60, 1848. 



— — Giebel. Fauna Vorwelt, Bd. iii, p. 747, 1852. 



— — Morris. Catalogue of British Fossils, 2nd ed., p. 295, 



1854. 



— — Oppel. Die Juraformation, p. 251, 1855. 



— — Simpson. Fossils of York. Lias, p. 37, 1855. 



— — Guembel. Beschr. d. Bayr. Alpen, p. 474, 1861. 



— — Oppel. Palaontol. Mittheilungen, p. 140, pi. 44, figs.. 



1, 2, 1862. 

 Phyiloceras subcakinatum, Tate and Blake. Yorkshire Lias, p. 297, 1876. 



Diagnosis. — Shell discoidal, extremely involute, inner volutions nearly concealed,- 

 outer whorl one-half the diameter of disk ; sides convex, inflated, covered with straight or 

 slightly flexed obtuse irregular radii, obsolete near aperture ; striae very numerous, fine, 

 annular, irregular, diverging ; siphonal area wide, with central ridge, and two flattened 

 bands on each side ; umbilicus narrow and deep. Aperture ovate, widest at the spiral 

 border and bevelled away towards the area. 



Dimensions. — Transverse diameter 100 millimetres; breadth of area 18 millimetres;, 

 height of aperture 50 millimetres ; width of whorl at the aperture 40 millimetres ; width. 

 of umbilicus 1 5 millimetres. 



Description. — Phylloceras subcarinatum has been long known to the Yorkshire 

 naturalists, and is remarkable for its dissimilarity from other congeneric forms ; still this- 



