MODERN CLASSIFICATION. 
245 
side with a projecting linguiforra process and two lateral grooves which extend to the 
opposite side of the shell. Septa symmetrical,, divided into four or six lobes each formed 
of a pair of digitations. The ventral lobe equals in length the adjoining principal lateral, 
which is longer than the lower lateral, and the columellar is small or absent. 
Genus Phylloceras, Suess. — Shell discoidal, highly involute, covered with very fine 
strise which describe graceful forward bent lines (fig. 147). Body-chamber short, mouth- 
border simple, with lateral lappets directed forward. Lobes numerous and very com- 
plicated, as many as eight or nine on each side. Saddles bladder-shaped and well rounded 
(fig. 148) ; body-chamber widely expanded and fan-shaped, with undulating radiations in 
Phylloceras heterophyllum, Sow, 
Fig. 146. — Disposition of the lobes Fig. 147. — Phylloceras heterophyllum, 
(d, l, l', a) in Phylloceras heiero- Sow. Side view showing the lines 
phyllum. of growth. 
Fig. 148. — Disposition of the lobes 
and saddles (d, l, l', a) in Phyll. 
heterophyllum. Sow. 
Professor Neumayr^ distinguishes, from the Dogger and Malm, four groups in this 
genus, of which the following are types : — I. Phyll. heterophyllum, Sow. ; II. Phyll. 
tatricum, Pusch ; III. Phyll. Capitanei, CatuUo ; IV. Phyll. ultramontanum, Zitt. 
This genus commences in the Trias with Phyll. debile, Hauer; Phyll Neojiirense, 
Quenst. ; Phyll. despectim, Mojs, ; Phyll. occultum, Mojs. In the Middle Lias Phyll. 
Loscomhi, Sow., Phyll. Zeies, d'Orb. In the Upper Lias Phyll. heterophyllum, Sow., 
Phyll. subcarinatum. Young. In the Oxfordian Phyll. tatricum, Pusch., Phyll. viator, 
d'Orb., Phyll. Hommairei, d'Orb,, Phyll. Zignoanum, d'Orb. In the Cretaceous rocks 
Phyll. subalpinum, d'Orb,, Phyll. Velleda, d'Orb. Dr. W. Waagen has figured and 
described^ several interesting species, closely allied to European forms, collected from 
the Upper Jurassic rocks of Kutch, Western India, by the Geological Survey of India, 
^ Neumayr, " Phylloceratten des Dogger und Malm," ' Jalirbucli der Geol. Reiclisaustiilt,' 18/1, 
bd. xxi. 
2 ' Palseontologia Indica,' pis, v, vi, vii, p. 25, 1875. 
