BAENID^;. 65 



distinct, but very narrow and shallow. The vertebrals are relatively wider than they are in any 

 of the other species of the genus. From the first vertebral there is cut off on each side an acces- 

 sory lateral scute, and this has much reduced its size; also, from its anterior end there is cut off 

 a small supernumerary vertebral, so that there are really 6 vertebrals, as in Chisternon. The 

 table herewith gives the dimensions of the vertebrals. The width of the central ones is really 

 somewhat greater than the figures indicate, on account of some lateral compression. 



The triangular supernumerary lateral scutes are each 39 mm. fore and aft, and 50 mm. 

 from side to side. 



The area usually occupied in turtles by the nuchal scute is broken up into 4 scutella? 

 unsymmetrical in form and size. Of these the extreme right and left are larger and much 

 alike in form and size; the median two are much unlike, one being very small. 



Behind the nuchal scutellae there are 13 marginals on each side. Usually the costo-marginal 

 sulci run along some distance below the costo-peripheral sutures. The first marginal extends 

 back from the border of the shell only 16 mm.; the fourth, 40 mm.; the sixth, 55 mm., and 

 rises above the costo-peripheral suture; the eighth, 53 mm.; the eleventh, 41 mm. The thir- 

 teenth is considerably smaller than the twelfth. As in other species of Ba'ena, there was no 

 supracaudal scute. 



The plastron (plate 10) is rather narrow, especially the hinder lobe. Its total length is 

 305 mm. The bridge has a width, fore and aft, of 115 mm.; a length, from the inner end to the 

 border of the carapace, of 95 mm. It rises considerably from the inner end to the outer. The 

 anterior lobe is 106 mm. long; 1 15 mm. wide at the base. The width diminishes gradually to 

 the gulo-humeral sulcus, then rapidly to the midline in front. The thickness ot the border of 

 the lobe is about 8 mm.; behind the entoplastron, about 6 mm. 



The hinder lobe is 98 mm. long; 120 mm. wide at the base. The lateral borders are 

 nearly straight and convergent to the ends of the femoro-anal 

 sulcus. Here the width is 71 mm. Behind this, the sides are 

 nearly parallel for a short distance; then they round rapidly to 

 the shallow hinder excavation. Just behind the inguinal notch 

 the thickness is 18 mm.; near the hinder extremity, only 7 mm. 

 The entoplastron is oval, 47 mm. long and 36 mm. wide. 

 The hyoplastrals extend along the midline 85 mm., and each 

 reaches laterally, behind the axillary notch, 105 mm. There are 

 large mesoplastrals. The median ends are 24 mm. wide, the 

 lateral ends, 61 mm. Each extends outward from the midline 

 125 mm. The hypoplastrals join along the midline for the distance of 75 mm.; the xiphi- 

 plastrals, 60 mm. 



The intergulars and gulars are of about the same form and size, all starting from a point 

 near the front of the entoplastron. The humerals are 63 mm. long and meet for some distance 

 behind the entoplastron. The pectorals occupy about 54 mm. of the midline; the abdominals, 

 about 48 mm.; the femorals, about 78 mm.; the anals, 37 mm. 



On the bridge of each side are seen 4 large inframarginals. These lie principally on the 

 plastral bones, but partly on the peripherals. 



The hvoplastra and hypoplastra send upward strong buttresses against the inner surfaces 

 of the first, and of the fifth and sixth costals respectively; but these buttresses, especially the 

 inguinal, do not extend inward so far as they do in the other species of the genus. The axillary 

 buttress is directed upward and forward toward the front of the first dorsal vertebra. Its 

 inner border is acute. At its upper end the buttress joins the first rib, which is wide and fur- 

 nisht with a sharp border; thus the partition bounding the sternal chamber anteriorly is 

 carried up to the first dorsal vertebra. The inguinal buttress, seen from behind, appears to be 

 about 30 mm. wide; but in front of it the sternal chamber extends far out toward the border of 

 the carapace. 



Baena escavada sp. nov. 

 Plate 11, figs. 1, 2; text-figs. 42, 43. 



The chelonite on which this species is based was obtained by Dr. J. L. Wortman and Mr. 

 Walter Granger in 1896, in the Torre jon deposits, at the head of Escavada Creek, in New 



5 



