ORDER II AMMONOIDEA 555 
(Fig. 1138), which is highly involute and compressed, with flat and narrow venter. 
Sutures with more or less acute lobes and saddles, as well as a number of adventitious 
and auxiliary inflections. Ventral lobe divided, and funnels monochoanitic. Aperture 
with hyponomic sinus, and the lateral 
outlines simpler than in the next family. 
Devonian, 
Family 3. Sageceratidae. Similar 
to the last, but lateral lobes bifid, and 
saddles acutely spade-shaped. Anti- 
siphonal lobe bifid. Aperture has sinuous 
lateral outlines with crests at the ventro- 
lateral ridges. 
Pseudosageceras, Diener; Sageceras, 
Mojs. (Fig. 1139). Permian and Trias. 
Family 4.  Hedenstroemitidae. 
Principal lobes and saddles with ceratitic 
outlines as in Discocampyli, but adven- 
titious lobes and saddles have Sageceras- 
like outlines. Antisiphonal lobe bifid and 
very long. Dorsal inflections more com- 
plex than in preceding families. Aper- 
ture with ventral crests. ; 
Hedenstroemia, Waagen; Anaheden- ees 
Caer HUTiingeri Weer Sie Uverane eeiente 
stroemia, gen. nov. Type A. (Heden.) ee pclae cis gs 










\ \ 
~\ \\ \\\ 
ANY 


Mojsisovicst, Diener sp. Trias. 
Sub-Order F. DISCOCAMPYLI. Hyatt. 
Primitive genera show close approximation to primitive types of Prolecanitidae. 
Bases of saddles retain the entire rounded outlines of Lecanites even in specialised genera, 
but the lobes become completely divided by fine marginal serrations or digitations. This 
purely ceratitic outline is maintained more or less in all growps except highly specialised 
genera, in which the saddles are completely divided and the discocampylic bases disappear. 
Antisiphonal lobe entire in primitive, but bifid or trifid in specialised forms, and zygous 
dorsal inflections assume the ceratitic outline in some genera. Ventral lobes very broad 
and short, and have very broad siphonal saddles in typical forms. 
The number of external inflections rarely exceeds three saddles and three lobes in 
primitive forms, and the first pair of lobes as a rule is very much longer and broader 
than the others. While the external saddles often assume approximately monophyllic 
outlines, the dorsal saddles commonly retain the broader and less differentiated aspect 
ot Lecanitidae, and saddles never become divided. The number of dorsal inflections is 
more limited in most forms than in Phyllocampyli, and when lengthened by additional 
inflections, the digitations are apt to be irregular. 
J. LECANITIDA. 
Compressed discoidal and involute forms. Compressed primitive genera have entire 
sutures with broad rounded saddles and rather narrow lobes, the ventral lobe being broad 
and shallow, and the siphonal saddle also broad. Involute shells generally have pro- 
_longed lateral suture-lines with an indefinite number of often irregularly proportioned 
inflections, which are really marginals arising from the division of a prolonged inner 
saddle or nearly straight, depressed lobe-like inner line. Dorsal sutures have similar 
characters and. the antisiphonal lobe, which is entire and pointed in primitive forms, 
usually remains entire on the sides and bifid at the extremities in specialised forms. 
