EMYDID&. 325 
The seventh peripheral has at its hinder sutural border a thickness of 13 mm. A rather 
prominent rounded keel runs along on the peripherals over the bridge. 
The broadest vertebral scute is the first. The second and third are of moderate width, with 
the sides somewhat bracket-shaped. 
Dimensions of peripherals. Dimensions of vertebral scutes. Dimensions of marginal scutes. 
Widt Vi ¥ 7 aes nae 7 _ . ..__) Lengt 
| No. | Height. of Pe of ia Ree ene fess Mi No,, | eet | Greens re 
| js b one So" in front.; width. in front. height. 
eee wk order. border. 7 es) : border. 
I 39 32 24 I 52 g6+ g6+ I 13 ae 
2 40 344 | 20 2 80 es 60+ 2 | 20 24 37 
3 41 36 22 3 73 40 60 4 23 40 
6 47 43 44 4 . 47 60 Tide I a 2, 27 42 
7 48 39 30 
The costo-marginal sulci run at a distance of about 20 mm. below the costo-peripheral 
sutures. On the under side of the nuchal and the first and second peripherals the marginal 
scutes are 28 mm. wide. 
On the visceral side of that portion of the carapace present (fig. 424) are exhibited the 
axillary and the inguinal buttresses and the shoulders of bone against which they abut. The 
424. seb / 
423. oy, 
Fics. 422-42¢.—Echmatemys cyane. Carapace and plastron of type. X }. 
5 DES P Pp yp f 
423. Portion of carapace. 
424. Portion of carapace, inner surface. ax. b., axillary buttress; c. p.6, sixth costal plate; ing. b., 
inguinal buttress. On the left are seen sorne neurals and the bases of the rib-heads. 
425. Two fragments of the plastron. 
axillary buttress has a maximum width of 25 mm. and is 12 mm. thick. It ascends within the 
first costal to a point 25 mm. or more above the upper border of the second peripheral, consider- 
ably further than the buttress ascends in FE. wyomingensis, No. 5987 and No. 5988, A. M.N. H. 
It abuts against an extremely prominent ridge, 12 mm. thick and 10 mm. elevation above the 
general surface of the costal. This buttress and ridge are therefore very different from those 
of the species just mentioned. The distance from the upper end of the buttress to the base of 
the rib-head is less than the distance from the summit of the buttress to the border of the 
second peripheral. In £. wyomingensis the former distance is much greater than the latter. 
The posterior buttress articulates for a moderate distance against the inner surfaces of 
the fifth and the sixth costals, about as far as in E. wyomingensts, but it appears that the but- 
