Dr. J. E. Gray on Indian Mud- Tortoises. 473 



Fig. 14. Tlie longitudinal axis of the nucleus entirely filled with gi-a- 



nules. 

 Fig. 15. Bud-like scion from a rosette of Epistylis Jlavicans, magnified 



about .300 diaui. : n, nucleus ; b, contractile vesicle. 

 Fig. 16. Encysted Epistglis Jlavicans, 

 Fig. 17. Brancli of Epistylis Jiavicans on which the nuclear formations 



described under figs. 10-14 occurred. For distinction from those 



of fig. 9 the nuclei are not visible. 

 Fig. 18. Large variety of Epistylis Jlavicam : .r, the parasitic (?) Flagellata 



seated on the peduncle. 

 Fig. 19. The parasitic (?) Flagellata under a higher power. 



Plate XVI. 



Fig. 1. Representation of the alimentary system of Epistylis Jlavicans. 

 The animals have been subjected to a carmine diet. The arrows 

 indicate the current of rotation of the coloured material (balls 

 of nutriment ) in the interior of the digestive body-cavity : 

 m, buccal orifice (entrance into the vestibulum) ; o, oesophagus ; 

 V, funnel-like termination of the oesophagus; d, canaliform 

 continuation of the funnel. The colour-balls issuing from the 

 funnel glide as spindle-shaped bodies (b) through the canal, 

 and project at b' with a little knob from its hinder opening; 

 n, nucleus. 



Fig. 2. The alimeutarj' tube of Epistylis Jlavicans isolated. The arrows 

 indicate the direction of the flow of the food : 7«, mouth ; 

 k & k', valvular partitions ; o, ojsophagus ; v, funnel ; d, canah- 

 form continuation of the funnel ; h, anus, from which a long 

 seta projects outwards. 



Fig. S. Alimentary apparatus of Ej)istylis plicatilis. 



Fig. 4. Branch of Epistylis 2'>licatilis : k, contracted animal ; ti, nucleus 

 with nucleoles ; b, contractile vesicle ; g, muscles. 



Fig. o. Posterior adherent extremity of the peduncle of Epistylis plica- 

 tilis : f, foot with sole. 



L. — On Indian Mud-Tortoises (Trionyx). 

 By Dr. J. E. Gray, F.R.S. &c. 



Before I saw the 'Annals' of last month, I was told that 

 Dr. Anderson had examined nearly two hundred specimens of 

 Indian mud-tortoises. I observed that I supposed he had 

 availed himself of my suggestion, and was about to give us a 

 paper worthy of his position in the Museum and University. 

 But when I saw the paper, this delusion was dispelled. The 

 paper might be shortly written thus : — The mud-tortoises of 

 India have been properly divided into two species. He might 

 have added, with truth and justice, that the species had been 

 well characterized, and their synonymy well made out ; but 

 this would show the ridiculousness of the vain boast Avhich 

 terminates his paper. The species are so distinct that 

 the native fishermen and market people kno^v them by dif- 

 Ann. & Mag. N. Hist. Ser. 4. Vol. ix. 32 



