36 CINOSTEKKIDJK. 



Sf/noj>sis uf the Si)ecies. 



I. Plastron small, the width of the posterior lobe not more than half 



that of the shell ; a narrow bridge connects the plastron with 

 the carapace; lobes of plastron slightly, if at all, movable. 

 Male with a patch of small horny, keeled tubercles on the 

 hinder side of the leg and another below the thigh. 



Gular shield well developed, triangular 1. odoratvm, p. 37. 

 Gular shield vestigial or absent 2. cariiiatum, p. 38. 



II. Plastron of moderate size, smaller than the opening of the shell, 



connected witli the carapace by a bridge, the width of which is 

 considerably less than the length of the front plastral lobe ; 

 • front and hind lobes movable ; plastron notched posteriorly. 

 Male with a patch of small horny, keeled tubercles on the 

 hinder side of the leg and another below the thigh. 



A. Front plastral lobe considerably narrower than the opening of 



the shell. 



Pectoral shields triangular, or forming 



a very short median suture 4. pensi/lvuiiicum, p. 39. 



Suture between the pectoral shields 



two thirds the length of that between 



the humerals ; gular shield not one 



third the length of the front lobe 



of the ])lastron 3. hirtijH-s, p. 38. 



Suture between the pectoral shields 



nearly as long as that between the 



humerals ; head and jaws without 



any spots 5. JIavcscens, p. 40. 



B. Front plastral lobe nearly closing 



up the shell (5. henrici, p. 40. 



III. Plastron narrower than the opening of the shell, connec*^ed 

 with the carapace by a very short bridge, the width of which 

 nearly equals the length of the front plastral lobe: front and 

 hind lobes movable ; plastron notched posteriorly, Male 

 without patches of horny tubercles on the hind limbs. 



Carapace tricarinate 7. scorpioides, p. 41. 



IV. Lobes of the plastron movable and completely closing the shell 

 in the adult, the pectoral and femoral shields being then in 

 contact Avith the axillary and inguinal ; plastron not or but 

 very feebly emarginate posterioily. Male without patches of 

 horny tubercles on the hind limbs. 



A. Carapace unicarinate. 

 Plastron slightly nicked posteiiorly , . 8. integrum, p. 42. 



