1870.] LANKESTER—NEWER TERTIARIES OF SUFFOLK. 503 
in the preceding Diestien epoch, the breaking up of the accumulation 
of that period having furnished the numerous cetacean remains, the 
box-stones, and the phosphatic properties to the Suffolk bone-bed. 
Like other ziphioid snouts and bones from this bed, the specimen 
bears the marks of terminated Pholas-borings. The mollusks appear 
to have penetrated the matrix which once surrounded the fossil, and 
to have been stopped by the peculiar properties of the dense bone. 
The specimen is 163 inches long; anteriorly it is complete, pos- 
teriorly it is broken at the same point as are all the ziphioid snouts 
from this bed, viz. in a plane corresponding with the anterior 
boundary of the nasal orifice above, and below with the junction of 
the palatine and maxillary bones. The solid fragment or rostrum 
which is preserved consists therefore of the maxillary, intermax- 
illary (the expanded portion being imperfect), and vomerine bones. 
It is much broader posteriorly than anteriorly, measuring 63 inches 
at its posterior limit and tapering gradually from that to a sub- 
acute anterior termination. 
Seen from above (Pl. XX XIII. fig. 2) it is somewhat flat, rising 
a little into convexity anteriorly and considerably raised at the pos- 
terior margin round a deep and wide fossa (#7 g), which is excavated 
in this part of the surface in connexion with a superficial groove (7 q). 
Seen from below (Pl. XXXITI. fig. 1) it is considerably arched, 
being highest posteriorly and elevated into a marked keel in the pos- 
terior third of the middle line, which is continued into a prominent 
vertical ridge, projecting from the posterior surface of the specimen. 
The lateral angles are also produced, so that the posterior region pre- 
sents a trifid appearance. The keel spreads out anteriorly into a wide 
convex area marked out on either side by. a ridge. Two lateral ridges 
on either side also run from behind forwards, passing somewhat ob- 
liquely towards the inferior surface as they proceed. The superior 
and most prominent of these probably marks off the maxillary from 
the intermaxillary component of the rostrum. The mest important 
feature presented by the inferior surface of the rostrum is its rather 
sudden approximation to the superior surface anteriorly, so that in 
profile (Pl. XX XIII. fig. 3) if appears to bend upwards like the bows 
of a boat, whilst a small portion (the most anterior) of the rostrum 
projects again forward from this like a bowsprit. Below and pos- 
teriorly to this most anterior part of the rostrum is a cavity 2 of an 
inch in diameter, extending axially to the rostrum (Pl. XXXITI. 
figs. 1 & 3, vc), the “remains of the primitive trough-like cavity of the 
vomer”’ as Professor Huxley calls it in describing Belemnoziphius. 
Seen in profile (Pl. XX XIII. fig. 3), the whole rostrum is not 
unlike the roughly cut hull of a sailing-vessel, with flat deck, keel 
below, tapering bows, and square stern of exaggerated breadth. 
The canals which are present in this rostrum, besides the axial 
vomerine canal, transmitted vessels, and nerves, are of the same 
nature as those seen in rostra of Belemnoziphius; at the same time 
they have not an exactly similar disposition. The fractured poste- 
rior superior border of the specimen presents on each side of the 
middle vertical ridge, more or less completely according to the degree 
