) 
74 PSEUDOCERATITES OF THE CRETACEOUS. 
volution is about 1 mm. from venter to line of involution. The transverse 
section is stouter than in second volution, the outline bemg helmet-shaped, 
and the venter elevated and beginning to be subacute. At this stage there 
is one large trifid saddle and one large lateral lobe, and the large inner 
saddle has two marginal saddles and one on.the line of involution. This 
enabled me to see that the first to third saddles and first to second 
lateral lobes of succeeding stages were made by division of the first 
nepionic saddles. The third lobe of the adult consequently represents 
the primitive lateral nepionic lobe, and the remainder of the saddles 
and lobes were derived from the division of the outlines of the magno- 
sellarian or second lateral nepionic saddles. In the zone of involution 
there is a deep antisiphonal lobe and a pair of large saddles with a pair 
of broad lobes and small saddles at the lines of involution. The specimen 
has the color and transparency of amber and the enlarged drawing 
(Pl. IX, fig. 2) represents what was seen. ‘There was a decidedly swollen 
joint at each septum of the three seen. <A collar was dimly seen, and 
there appeared to be but one long funnel reaching across the chamber. 
This seemed to be the fact, and yet I do not think it was clear enough to 
be considered certain. Such a long funnel would be a remarkable case of 
arrested development, especially when a collar was present. It may be 
that the appearances were due to the entire absence of any true funnel. 
This last view would entirely reverse the statement and show a_ high 
degree of acceleration, since the disappearance of the funnel usually takes 
place later in life in most Jurassic and Cretaceous forms. In the neanic 
substage, perhaps in the ananeanic, above mentioned, the first three saddles 
still show the curvature of the great first lateral nepionic saddle. The 
ventral lobe is broad, as in the adult. The siphonal saddle is prominent 
and broad, but as yet shows no digitation, only a few faint indentations. 
The arms of the lobe are just passing from the entire hastate to the trifid 
type. The first two lateral lobes are im the same condition, but the saddle 
remains entire and club-shaped. In fact, at the stage immediately pre- 
ceding this, the three principal derivative saddles and lobes must have been 
almost exact repetitions of those of Prolecanites among Goniatitine. The 
fourth saddles are entire, but rather short, and beyond are three saddles still 
very primitive im outline. The dorsal has an entire antisiphonal, more 
club-shaped than in the younger stage, and there are four other pairs of 
