CHELONIID^. 219 



present on one side are not represented by their fellows ol the opposite side. There is therefoi e 

 both a redundancy and a shortage. Evidently neither fourth peripheral is present. There 

 are representatives of 3 peripherals, probably the tilth, sixth, and seventh of the left side. 

 The supposed fifth (fig. 278) is 99 mm. long and consists of two plates which meet each other 

 at an acute free border. The two succeeding this, the sixth and the seventh, are damaged, 

 but the faces make a smaller angle with each other. The fifth presents an extremely shallow 

 rib-pit, located in the hinder half of the length. It is highly probable that these peripherals 

 belong to a turtle ot some other genus. 



On the left side are three peripherals following in their natural order. Each of these 

 has three taces, a somewhat convex upper face, a flat lower face, and a channeled visceral 

 face. The rib-pit of the first one is a little behind the middle of the length. This bone 

 resembles one in lot number 2215, of the American Museum mentioned above; but both sides 

 of the latter are flat. The bone under description is 125 mm. long, 64 mm. wide in front, and 

 22 mm. thick. The next one is a very little shorter and slightly narrower. It presents no pit. 

 This is in the front end of the next peripheral, close to the suture. This next bone is 115 mm. 

 long, 46 mm. wide anteriorly and 21 mm. thick. In general, the section of it resembles that 

 of the first of the three here described. Bones corresponding to the second and third of those 

 just described appear to be represented on the right side of the animal. On this side the pit 

 which was in the front end of this third of the side is moved forward to the left junction between 

 the two bones. On this side, too, the hinder of the two is broken, but both ends of it appear 

 to be present. Following what almost certainly is its hinder end is a similar peripheral, with 

 its hinder end missing. This bone has a small pit for a rib. The inner, or visceral face, is 21 

 mm. wide. 



Besides these peripherals there are four others present which require consideration. Two 

 of these are corresponding bones of opposite sides. Fig. 279 represents the one taken to 

 belong to the right side. It will be observed that there is a decided change in the direction 

 of the curve at the supposed anterior end. This bone is 88 mm. long and 48 mm. wide at the 

 sulcus. On its channeled inner face, at the end of the sulcus, is a deep pit for a rib. A portion 

 of another peripheral is attacht to what is supposed to be the anterior end of this curved 

 peripheral. Its inner face is narrower. 



The curved peripheral of the other side has, at some period of life, had the supposed 

 anterior end damaged, so that it has the appearance of having formed a false joint with its 

 contiguous peripheral. Attacht to the hinder end of this bone is another peripheral (fig. 280) 

 whose fellow is not present. It is 105 mm. long. The inner face is channeled but there is 

 no pit. One end, supposed to be the posterior, is narrow only 24 mm. wide. It is probable 

 that this bone is the eleventh and that the narrow end joined the pygal. 



To add to the difficulties, there is present what appears to be the left half of a pygal bone. 

 This was 86 mm. wide and 65 mm. high. It articulated suturally with a suprapygal and 

 laterally by its whole height with the contiguous peripherals, the eleventh pair; but certainly 

 not with the one regarded above as the eleventh. 



Portions of a large thick plastron are present. One piece may be part of a hyoplastron. 

 A free border, probably the outer, is digitated. One border articulated suturally with another 

 bone, supposedly the hypoplastron. 



On the nuchal bone the sulcus bounding posteriorly the nuchal scute or the first marginal 

 is 44 mm. behind the free border, near the midline and 54 mm. from the border at the outer 

 end of the bone. The limits of the nuchal scute can not be made out. On the first and second 

 peripherals the costo-marginal sulcus is seen running nearer the costal margins of the bones 

 than the free margins. Posterior to these the costo-marginal sulci doubtless lay on the intervals 

 between the costal and peripheral bones. Each peripheral is crost by a sulcus separating 

 two marginals. 



The outer surfaces of all the bones are smooth, except that they are markt by numerous 

 vascular grooves. 



In the paleontological collection at Rutgers College, New Brunswick, New Jersey, are 

 found one peripheral and one complete costal which are labeled as belonging to this species 

 and as having come from the Miocene marl at Tinton Falls. There is probably an error in 

 the locality. 



