426 AMERICAN TESTUDINATA. Part II. 



GENERA OF THE SUB-FAMILY OF CINOSTERNOID^E PROPER. 



I. CiNOSTERNUM, Spix. The jaws are strong ; their horizontal alveolar surfaces are 

 broad, and they seem well fitted for crushing ; their strength comes from thick- 

 ness, and not from height. The head is very broad : the upper maxillaries spread 

 wide apart backward ; the sides of the head continue to spread back of them till 

 about midway between the eyes and ears ; and thence backward they approach 

 each other. They also spread rapidly apart from above downward, just back of 

 the eyes. The front part of the head over the mouth is low ; its roof between the 

 eyes is broad ; and the eye-orbits open sidewise and forward, not upward. The nose 

 is short ; its sides curve out somewhat from above downward, and its roof reaches 

 as fiir forward as the jaw under it. The mouth is very short, and, as the upper 

 maxillaries spread so wide apart backward, it is very broad behind. The outer 

 surface of the maxillaries curves outward under the eye, and then turns sharply 

 inward to the alveolar edge ; but at the symphysis the jaw is drawn down to 

 a sharp point or a short chisel-edge, and the outer surface at the end slants 

 backward less than it slants inward at the sides. The horizontal alveolar surface 

 is very broad, narrowest at and near the symphysis, and widening fast thence 

 backward to the hind end. The lower jaw is low, but its outer surface curves 

 far Tjackward from the end and inward from the sides, and its alveolar surface 

 is broad ; thus it is thick and strong. The alveolar edge is bluntly rounded at 

 the front end, and not drawn out to a sharp point. Th6 alveolar surface is 

 narrowest at the symphysis and on either side of it, but widens fast thence 

 backward, and is broadest at the hind end ; at and near the angle it is almost 

 flat from side to side, but its outer edge rises considerably about the front end. 

 The outer surface of the jaw curves outward considerably below the alveolar edge, 

 thus making the jaws shut the closer. 



No species of this genus are known to occur within the limits of the United 

 States ; but there are several in Central and South America, which have gener- 

 ally been confounded with the Testudo scorpioides of Linnasus. Major LeConte 

 was the first to distinguish them carefully.^ It is true the species from the Brazils 



^ Dumeril and Bibron, (Erp. gen. 2 vol. p. 32,) the genus Cinosternum, (Proc. Acad. Nat. Se. Phil, 



as well as Gray, (Cat, Brit, Mus. 1844, p. 32,) agree 1854, p. 180,) has clearly shown that the Brazilian 



in considering Bell's Cinosternum shavianum, and specimens constitute a distinct species from that of 



Spix's Cinosternum longicaudatum and brevicauda- Surinam, wliieh is tlie old Linna;an species, and that 



turn, as synonymes of Testudo scorpioides, Lin. ; the Mexican is still different. I have myself exam- 



but Major LeConte, in his interesting monograph of ined the specimens upon which his descriptions ar« 



