PHYLLOCERAS LOSCOMBI. 419 



In the Upper Lias Phyll. heterophi/llum. Sow., Phi/Il. siibcarinatum. Young. 



In the Oxfordian we find Phjll. tatricum, Pusch ; Phyll. viator, d'Orb. ; Phyll. 

 Ilommairei, d'Orbig. ; Phyll. Zignodianum, d'Orbig, 



In the Cretaceous rocks we find Phyll. stibalpinum, d'Orbig., Phyll. Vellidce, d'Orbig. : 

 and Professor Waagen has figured and described^ several interesting species closely allied 

 to European forms from the Upper-Jurassic rocks of Kutch, Western India. 



Phylloceras Loscombi, Sowerby. PI. XL, figs. 4, 5. 



Ammonites Loscombi, Sow. Mineral Conch., vol. ii, pi. 183, 1817. 



Globites — Haan. Ammon. et Goniatit., p. 147, 1825. 



Ammonites — cTOrbigny. Pal. rran9.,Ter. Jurass., p. 262,pl. 75, 1842. 



— LoscoMBii, Morris. Catalogue of British Fossils, p. 173, 1843. 



— HETEROPHYLLUS NUMiSMALis, Quetist. Cephal., p. 100, tab.vi, fig. 5, 1849. 



— — — Oppel. Mittl. Lias, p. 48, tab. ii, fig. 9, 



1856. 



— Loscombi, Oppel. Juraformation, p. 162, 1856. 



— — Bumortier. Depots Jurassiques Bassin du Rhone, t. iii, 



p. 78, 1869. 

 Phyllocekas — Neumayr. Zeitschr. Deutsch. geol. Gesell., Bd. xxvii, 



p. 903, 1875. 



— — Tate and Blake. Yorkshire Lias, p. 296, 1876, 



Diaynosis. — Shell very thin, discoidal, compressed; whorls wide, four fifths involute; 

 sides flattened and slightly convex, covered with delicate, transverse, biflexed striae which, 

 on passing over the narrow, round siphonal area, develop prominent folds ; aperture 

 oblong, widest near the spiral suture ; umbilicus narrow, exposing the inner whorls. 



Dimensions. — Transverse diameter 140 millimetres ; width of umbilicus 20 milli- 

 metres ; depth of the last whorl 75 millimetres; height of aperture 70 milUmetres; 

 transverse diameter 33 millimetres. 



Description. — This beautiful shell is a very characteristic fossil of the " Green Ammo- 

 nite-bed," Middle Lias, near Charmouth. It is here nearly always found firmly em- 

 bedded in the matrix, so that a correct outline of the shell is seldom obtained. The 

 specimen I have figured is one of the finest I have seen. The shell is extremely thin 

 and lustrous, of a discoidal figure, and covered with delicate striae on the body-chamber, 

 and with small, biflexed ribs on the inner whorls. The shell is thickest around the spiral 

 suture near the umbilicus, and some specimens have likewise an elevated ridge or longi- 

 tudinal carina rising about the middle of the height of the whorl ; from this elevation 

 proceed a number of oblique striae which extend backwards towards the area. In the two 

 best specimens I possess the longitudinal carina and the oblique backward-directed striae, 



1 1. ' Palaeontologia Indica,' Ser. ix. 2. (Jurassic fauna of Kutch) p. 25, pis. v — vii, ix, 1875. 



