﻿DUMORTIERIA LEVESQUEI. 241 



Dumoktieria Levesquei (d'Orbigny). Plate XXXVII, figs. 6 — 8; Plate XLV, 



figs. 15, 16. 



1824. Ammonites undulatps, Stahl (non Smith). Correspbl. wiirttemberg. 



landw. Ver., Bd. vi, p. 49, fig. 10 (P). 1 

 1830. — — Zieten. Verstein. Wiirtt., pi. x, fig. 5. 



1830. — solaeis, Zieten (non Phillips 2 ). Ibid., pi. xiv, fig. 7. 



1842. — Letesquei, d'Orb. Cepli. jurass. ; Pal. Fran*?., pi. lx, p. 230 



(inscribed on tbe plate as Am. solan's, 

 Pbillips). 

 1853. — — Ohapuis et Dewalque. Foss. Luxembourg ; Mem. 



cour. et Mem. des sav. etrang., torn, 

 xxv, pi. xi, fig. 2. 

 1874. undulatus, Dumortier. Bass. Rhone, iv, p. 65. 



1885. Haepoceeas Letesquei, Haug. Beitr. Monogr. Harpoceras ; Neues 



Jahrbuch fur Mineral., &c, p. 662. 

 1885. Ammonites falcofila, Quenstedt. Amm. Schwab. Jura, pi. liv, figs. 28, 



30, 31. 

 1885. — cf. undulatus, Quenstedt. Ibid., pi. liv, fig. 27. (A form 



transitional to Dum. pseudo- 

 radiosa.) 

 1887. Domoetiebia Levesquei, Haug. " Polymorphidse ;" Neues Jahrbuch fur 



Mineral., &c, Bd. ii, p. 129. 



Discoidal, slightly compressed, carinate. Whorls ornamented with somewhat 

 distant, direct, ventrally-inclined ribs. Ventral area somewhat flattened, divided 

 by a small rounded carina. Inner margin not defined, convex. Inclusion, about 

 one-third. Suture-line with long siphonal and superior lateral lobes, causing a 

 deep siphonal saddle. 



As this is the typical species of the genus, I much regret that I have not been 

 able to obtain any better material for figuring. The fragment, depicted PI. 

 XLV, figs. 15, 16, agrees exactly with d'Orbigny's representation, except that its 

 ribs are a little closer. 



The complete specimen, figured PI. XXXVII, figs. 6 — 8, differs from 

 d'Orbigny's in certain respects; but it agrees exactly with Zieten's delineation of 

 Am. Solaris (non Phillips). It is a more advanced form than d'Orbigny's — its 

 ribs are closer together, and have a more forward inclination — its whorls are 



1 I am indebted to Dr. Haug's " Polymorphidse " for this reference, which I have not been able to 

 verify (see p. 242). 



2 Am. Solaris, Phillips, ' Geol. Torks,' 1st ed., pi. iv, fig. 29, has all the appearance of Pleuro- 

 ceras spinatum. 



31 



