BAENIDA. 8 
vertebral runs forward and inward to the midline. The table below gives the dimensions of 
the vertebral scutes. These are narrower than they are in B. arenosa of the same size, and 
the third is longer than in any of the described species. There are 5 small marginal scutes 
4 ae a ee lying in front of the first vertebral. Two of these, quadrilateral 
in form about 26 mm. long and 20 mm. wide, occupy respectively 
Vertebral. | Length. Width. 
| the night and left thirds of the front border of that vertebral. A 
a pentagonal scute 25 mm. from side to side occupies the middle 
2 third. It measures 15 mm. fore and aft; and its narrowed front 
3 92 75 scarcely reaches the margin of the shell, since two other small 
4 ig a scutes come in front of it, one on each side. No sulcus is seen 
. - 
along the midline. 
The lateral marginals of B. emilia are higher than they are in 
either B. arenosa or B. clara. The upper border of the one below the-anterior angle of the third 
costal scute stands about 50 mm. above the lower edge of the shell. In the specimen of B. 
arenosa, No. 1115, larger than the shell being described, the corresponding marginal hardly 
reaches 40 mm. The: upper borders of the marginals of B. emilie appear to fallow closely 
the sutures between the peripheral bones and the costal plates. 
There appear to be 13 marginals on each side, including the minute anterior one. 
The epidermal sulci of the carapace are deeply imprest; those of the plastron are rather 
obscure. The intergulars reach about two-thirds the distance to the humero-gular sulcus. 
There is a row of 5 inframarginals on each side. As to the other plastral scutes, it is not 
observed that they are especially different from those of B. arenosa. 
It is possible to trace the sutures between all the bones of the shell, except those sur rounding 
a few of the anterior neurals and some of the posterior peripherals; but even these may be 
located approximately. 
It will be observed that the nuchal does not have the great antero-posterior extent that it 
does in the recent Pleurodira. The neurals are in general elongated hexagonal, with the broad 
end forward. The first and second measure together 83 mm., and the Font one is probably 
a little the shorter. Of their width one can not be certain. The third is 55 mm. long, and 
apparently 30 mm. wide, the fourth, 43 mm. long, 27 mm. wide; the fifth, 43 mm. long, 31 mm. 
wide; the sixth, 35 mm. long, 32 mm. wide; the seventh: 30 mm. long, and the same in width; 
the eighth, 30 mm. long, and 34 mm. wide. Behind the last neural comes the pygal, 30 mm. 
long and 60 mm. wide. No suprapygal is found between the last neural and the pygal. The 
eighth costal plate occupies the whole lateral border of the eighth neural and, in addition, 
the postero-lateral portion of the seventh neural. 
The nuchal bone has a fore-and-aft extent of 37 mm. Its width from side to side is about 
50 mm. in front and about 85 mm. behind. 
There are almost certainly 12 peripherals on each side. The most anterior sutures are 
easily distinguisht; but, for various reasons, not the posterior ones. Over the bridges the 
sutures between the peripherals are continuous with the sutures between the costal bones; 
posteriorly, there is not this correspondence. The sutures are not traceable, but there is 
undoubtedly one between each two epidermal sulci. 
On the plastron all the sutures are easily distinguisht. ‘The total length of the plastron is 
320mm. The epiplastra meet in the midline by a suture 13 mm. long; the length of each bone 
is 42 mm. The entoplastron resembles that of 6. arenosa, as figured by Leidy ( (Cont. Ext. 
Fauna W. Terr., pl. xv, figs. 4, 5). Its length is 40 mm.; its breadth 34 mm. The suture 
between the hyoplastra is g6 mm. long. The ae ool meet in the midline for a space 
of 33 mm. At their outer ends they are 75 mm. wide. The suture between the hypoplastra 
is 87 mm. long. The xiphiplastral suture is 50 mm. long, and each, measured at its anterior 
end, is 50 mm. wide. The anterior and posterior buttresses of the plastron are like those of 
Be arenosa. 
The intergulars measure on the midline 18 mm.; the gulars, 9 mm.; the humerals, 51 mm.; 
the pectorals, 84 mm.; the abdominals, 42 mm.; the femorals, 64 mm.; the anals, 54 mm. 
On the bridge are 5 inframarginals. 
In the middle line above there are some longitudinal ridges and grooves and some irregular 
elevations, which are rudiments or vestiges of an ornamentation similar to that of B. arenosa. 
6 
