KACHUGA. 3! 



Synopsis of tlie Species. 



A. Third vertebral shield forming a broad suture 

 with the fourth, which embraces four neural 

 plates. 



a. Second vertebral shield with straight trans- 

 verse posterior border. 



a'. Alveolar surface of upper jaw extremely 

 broad, the median ridge nearer the outer 

 than the inner margin ; bony choanae be- 

 hind the orbits K. lineata, p. 40. 



b'. Alveolar surface of upper jaw narrower, 

 the median ridge nearer the inner than the 

 outer margin ; bony choanae between the 

 orbits K. trivittata, p. 41 . 



Fig. 12. Shell of Kachuga trivittata. 



b. Second vertebral shield pointed or produced 



behind, entering the third K. dhongoka, p. 41. 



B. Fourth vertebral shield pointed in front, nar- 

 rowly in contact with the third, embracing 

 five neural plates. 



a. Third vertebral quadrangular, much longer 

 than broad, posterior border straight or 

 slightly convex K. smithii, p. 42. 



