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PROCEEDINGS OP THE NATIONAL MUSEUM. 



VOL. 50. 



little rounded, whereas in B. hatcheri it rounds rapidly. The median 

 portion is broadly excavated. The anterior end is also rather broadly 

 truncated. The nuchal region projects slightly beyond the general 

 contour of the carapace. The hinder border lateral to the median 

 emargination is scalloped as in tlie other species of the genus. Be- 

 cause of the missing portions of this border the number of these scal- 

 lops can not be determined. 



The course of only a few of the costal sutures can be determined ; 

 all others are obliterated through coossification. The sulci although 

 shallowly impressed are quite clear. The ornamentation of the cara- 

 pace consists of ridges and furrows. The former are short, sometimes 

 straight, usually bent, or anastomosing. The general effect is much 

 the same as the sculpture in Thescelus insiliens Hay, described as 

 resembling " shagreened leather," though coarser in this specimen. A 

 considerable area within the second vertebral scute has the surface 

 smooth.. The sculpture of the plastron is of the same general char- 

 acter as on the carapace but finer in its pattern. 



The nuchal scute is pentagonal, wider than long, and bordered on 

 either side by a small triangular first marginal, see plate 32. In this 

 it resembles the nuchal region in Baena rlparia^ except in that species 

 the nuchal is divided. The nuchal is 1?> mm. long; a greatest width 

 of 27 mm. ; width of free border 16 mm. The second marginal is 27 

 mm. long on the free border ; the third 28 mm. ; the fourth and fifth 

 42 nmi. each. 



The vertebral scutes as in all Cretaceous Baenidae are wider than 

 long. The sides of the first are parallel until they meet the marginal 

 sulsus, then they tui-n in toward the center, thus making the scute six 

 sided as in B. anilqua (Lambe). The sides of the succeeding ver- 

 tebrals are but slightly bracket-shaped. Their principal dimensions 

 will be f()und in the accompanying table: 



Within the area of the fifth vertebral there is a decided median 

 longitudinal ridge, the only indication of a carina. 



The costal scutes show nothing particularly characteristic. 



The number of marginal scutes can not be determined. The first 

 marginal extends back from the border only 9 nmi., the second 20 

 mm., the fifth 33 mm., the last one 31 mm. 



The plastron is relatively short with a narrow tajiering anterioi' 

 lobe and a wider truncated posterior lobe with slight emargination. 



