APPENDIX. 
40 
with its deep postero-inferior concavity in cross section, is conclusive as 
to its relations. The form is not horizontally expanded as in Megaptera, 
nor attenuated as in Balaena, but has rather the proportions seen in 
Reinhardt’s figure of the young Balaena mysticetus : (Otn Rordhvalen 
pi III.) That is, it has subparallel anterior and posterior sides ; the ex- 
tremity alittle widened by the production backwards of the posterior por- 
tion. The anterior portion also somewhat, though less, protuberant. The 
whole extremity truncate and remarkably thickened. Thus it is nineteen 
inches long, the anterior tuberosity seventeen inches deep, the inferior out- 
line nearly straight. The orbital concavity, which is continuous with the 
•optic foramen, opens behind the posterior tuberosity and is defined exte- 
riorly by the expanded posterior margin of the bone. Thus the great tube- 
rosity which gives character to the bone was above and in front ot the eye. 
The portion of the rn'indibli preserved presents marked characters. 
The inner face is slightly concave, or plane, the external, strongly convex. 
’The inferior edge is narrowed, and the superior scarcely less so ; the 
inner face rounds a little to the former, and to a wide groove just 
below the latter. This groove is one inch wide near the middle of 
■the ramus, and is marked by a series of many small foramina. 
'These are closer together in the anterior, and regularly more widely 
.spaced to the posterior portion. Thus anteriorly they are 2.5 inches 
apart ; posteriorly four inches separate them, and near the extremity 
,of the series, six inches. I failed to find any foramina on the ex- 
ternal face of the ramus. It is difficult, however, to believe that they 
are totally absent ; it may be that they are confined to the anterior portion, 
which has not been preserved. This peculiarity, it entirely established, 
marks the species as quite distinct from any heretofore known from char- 
acters of the mandible. The depth in this species at the first point where 
The foramina are four inches apart, is fourteen inches. 
There are some other pieces apparently belonging to the cranium, whose 
.exact positions I cannot now assign. < )ne of these looks like a segment of 
a ramus of the lower jaw, but the contraction of the superior and inferior 
outlines is too great. One face is plano concave, the other convex flat- 
tened, with oblique superior and inferior faces, the latter the widest. 
Depth of plane, ten inches ; depth exterior flattened face, 7.75 inches. 
Depth six inches from same point, 7.5 inches. The second uncertain 
fragment is long and with parallel margins. The outer face is strongly 
convex ; the inner, at one extremity concave, so that a section would be 
halt a crescent (the lower portion being lost.) The inner face gradually 
becomes convex, though not strongly so, and the long diameter is trans- 
verse, while it is vertical at the anterior end. The former is seven inches ; 
the latter eight inches. The fragment looks like the extremity of a pro- 
