148 PSEUDOCERATITES OF THE CRETACEOUS. 
outlines such as appear in Béhm’s figure,“ but there are also regular trifid 
bases to the first lateral saddles. The former arise from the irregular 
growth of the marginal saddles of the first or outer (originally bifid) arm 
of the first lateral saddle, making sometimes a simple triple division, and 
sometimes this outer arm itself becomes trifid, equally or more or less 
unequally, as in Bohm’s figure. The variation of the sutures is very 
considerable in this species, but there seems to be, so far as my material 
reaches, no sufficient grounds for the separation of specimens having trifid 
first lateral saddles from those having this part bifid. In fact one 
specimen shows early in the ephebic stage a bifid first lateral on one side 
and a trifid saddle on the other side of the venter, i. e., the two arms 
of the first lateral on one side are regularly bifid and on the other the 
inner arm is trifid and the outer arm bifid. Occasionally this outer arm 
may have four marginals. In one specimen the inner arm is bifid and the 
outer arm has three minute marginals. In one specimen again (PI. XVI, 
fig. 5) there are three arms, each regularly subdivided by a median 
marginal lobe. This saddle can perhaps be best described in general 
terms as having three arms derived from an original bifid form and 
usually preserving a record of this original form in the shortness of the 
outer marginal lobe as compared with the second marginal and also in 
the usually bifid outline of the base of the third or innermost arm. Often, 
as in Pl. XVI, fig. 8, the inner arm is sufficiently separated to be counted 
as a second lateral saddle. 
The specimen described by Hamlin in Syrian Fossils’ is fine only on 
one side and the supposed shell ‘‘the thin test almost entire” does not 
exist. Hamlin was misled by the smooth surface and the presence of a 
thin brown layer. That this is not the shell is shown by the sutures, 
which are somewhat worn, not showing the denticulations plainly. The 
living chamber is obviously nearly complete and is a trifle less than 
one-half of a volution in length. IJ have examined twenty-two specimens 
of this species and not a single one had even fragments of the shell 
preserved and many were incrusted with ostreans and bryozoa. There is 
no positive proof that these ammonites were living members of the fauna 
in which they were found, but there are obvious reasons in their aspect 
a4 Ueber Amm. pedernalis: Zeitsch. Deutsch. geol. Gesell., Vol. L, 1898, p. 199. 
’Mem. Mus. Comp. Zool., Vol. X, No. 3, 1884, p. 11. 
