1S93.] 219 [Baur. 



eal ridge ; seven to eight pairs of pleuralia, all separated by neurals ; a 

 single neural between the first pair of pleurals. 



Type, Trionyx muticus Les. 



There is one group left, consisting of three species, which cannot be 

 united with any of the preceding genera, but which come nearest to As- 

 pidonectes and to Pelodiscus. This group consists of the Trionyx gangeti- 

 cus Cuvier, Trionyx leithii Gra}- and Trionyx hurian Gray. I shall use 

 the generic name laola for this group proposed by Gray in 1873 for Tri- 

 onyx leithii. 



Isold Gray. 



Posterior nares reduced in size by the inner extension of the maxilla- 

 ries. Alveolar surface of lower jaw without a strong longitudinal sym- 

 physeal ridge ; eight pairs of pleuralia, the posterior ones meeting in the 

 middle line ; two neurals between the first pair of pleurals. 



Type, Trionyx leithii Gray. 



The Trionyx indicus Gray, placed by Fltzinger with Aspidonectes, has 

 been separated by Gray as long ago as 1844 under the generic name of 

 Chitro,. This genus, as well as Pdockelys Gray (1864), Cycloderma Peters 

 (1854) and Cyclanorhis Gray (1852), I accept in the way as they have 

 been used by Boulenger in the British Jfuseum Catalogue. 



I give now a table of the different genera, with the type species and 

 their original locality, and also the names of the other species with their 

 original localities. 



Trionyx Geoffr., 1809 (name), Wagler {Emyda Boul.). 



1. Type, Testudo punctata hactiixde, 1788. 



Exact locality of type not known, India. 



2. Trionyx vitaita Peiers, 1854. 



Locality of type, Goa, West Coast of British India. 



3. Trionyx scutata Peters, 1868. 



Locality of type, Pegu, British India. 



Cycloderma Peters, 1854. 



1. Type, Cycloderma frenatum Peters, 1854. 



Locality of type, Zambesi river. East Africa. 



2. C. aubryi A. Dum., 1856. 



Locality of type, Gaboon, West Africa. 



Cyclanorhis Gray, 1852. 



1. Type, Cryptopus senegalensis Dum. et Bibr., 1885. 



Locality of type,* Senegal, West Africa. 



2. G. elegans Gray, 1869. 



Locality of type. West Africa. 



*The real type of Cyclanorbis is Cyclanorhis pelirsii Gray, 1852, from Gambia. 



