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BAENIDZ. 77 
is a groove. From a point a little behind the center of each vertebral scute a few folds radiate 
to the ends and angles of the scutal areas. Outside of these areas the surface of the shell is 
somewhat uneven. 
The anterior neurals are widest in front, very narrow behind. The three or four posterior 
are wider. The sutures are somewhat irregular. Only 7 neurals can be determined. The 
ee seventh is larger than the others and corresponds to the seventh 
and eighth costal plates; but no suture can be seen crossing it. 
The nuchal bone is slightly broader than long, 46 mm. by 35 
| — mm. The pygal, somewhat damaged, is broader than long. 
a ‘i The peripherals do not differ greatly in height, this being about 
7 57 27 mm. ‘There were apparently 12 of these bones on each side. 
68 61 The sulci are distinctly imprest, but narrow. The nuchal 
50+ go+ j x ome nae : : a ‘ . 
| scute 1s distinctly divided into a right and a left. At each side of 
= it is a minute triangular first marginal. The second marginal is 
33 mm. long on the free border; the third, 39 mm.; the eighth, 38 mm. The dimensions of 
the vertebral scutes are shown in the table. 
(Vertebral. Length. | Width. 
ApwWrn He 
aN 
‘ ac infm ™. : 
Se 
Fics. 59 AND 60.—Baéna riparia. Type. 3. 
59. Carapace, showing bones and scute areas. 
60. Plastron. ab, abdominal scute; an, anal scute; ent, entroplastron; ep, epiplastron; fem, femoral scute; g, 
gular scute; hum, humeral scute; hyo, hyoplastron; hypo, hypoplastron; infm, inframarginal scutes; 
mes, mesoplastron; pec, pectoral scute; x1ph, xiphiplastron. 
There are on each side 5 costal scutes, a small supernumerary one being situated on each 
side of the first vertebral. Whether there are 13 or 14 marginals is uncertain. There is no 
supracaudal scute occupying the midline over the tail. 
The plastron (plate 18; text-fig. 60) is 262 mm. long on the midline. Its width is close to 
200 mm. As in the other species of the genus, it sends upward strong axillary and inguinal 
buttresses. The former rise to within 25 mm. of the first dorsal vertebra. They are joined 
