564 Mr. C. T. Regan on the 



Synopsis of the Genera. 



I. Prsecaudal vertebrae normal, with the ribs attached to simple para- 



pophyses and the neural arches without lateral processes; end of 

 transverse process of fifth vertebra appearing as a rugose plate 

 behind the lateral cutaneous area. 



A. Head somewhat compressed and elevated ; tail and caudal ver- 



tebrae normal, 



1. Mesopterygoid smaller than metapterygoid ; pelvics behind the 



dorsal. 



Gil'-membranes free from isthmus Nangra, 



Gill-membranes attached to isthmus Qagata. 



2, Mesopterygoid large, extending to hyomandibular above the 



reduced metapterygoid ; pelvics below the dorsal. 



£!retkistes. 



B. Head depressed ; tail long and slender ; caudal vertebrae with 



laminar neural and haemal spines and lateral laminar processes 

 which may form external series of bony plates. 



Pelvics behind the dorsal Breitensteinia. 



Pelvics below the dorsal Sisor. 



II. Anterior prsecaudal vertebrae with a series of processes on each side 



directed upwards and outwards from the bases of the neural 

 arches ; head depressed. 



A. Lips normal ; mesopterygoid large, extending forward below the 



palatine and backwards to the hyomandibular ; complex cen- 

 trum rigidly united, but not ankylosed to cranium ; para- 

 pophysis of fourth vertebra a half-cylinder, of fifth a stout 

 horizontal process ending just beneath the skin. 



1. Ribs inserted on normal transverse processes ; pelvics behind 



the dorsal; gill-membranes free or narrowly attached to 



isthmus. 



Thorax without longitudinal plaits Bagarius. 



Thorax with longitudinal plaits ; palate toothed. . . . Euclyptosternuin. 

 Thorax with longitudinal plaits ; palate toothless . . Glyiitosternum. 



2. Anterior ribs sessile, the rest on transverse processes which are 



forked at the base ; pelvics below the dorsal ; gill-membranes 

 broadly attached to isthmus Pseiidecheneis. 



B. Lips expanded and reflected ; mesopterygoid not reaching hyo- 



mandibular ; complex centrum ankylosed with cranium ; para- 

 pophyses of fourth and lifth vertebrae united to form a complete 

 cylinder on each side ; ribs on transverse processes which are 

 forked at the base ; gill-membranes broadly attached to isthmus. 

 Teeth all pointed ; gill-openings extending on to 



lower surface Parexostoma. 



Teeth all pointed ; gill-openings not extending on to 



lower surface Euchiloglnnia. 



An outer series of blunt compressed teeth Exostoma. 



