XXIX. INDIAN CYPRINOID FISHES BE 

 LONGING TO THE GENUS GARRA, WITH 

 NOTES ON RELATED SPECIES FROM 

 OTHER COUNTRIES. 



By Sunder l^.\h Hor.\, M.Sc, Assistant Superintendent, 



Zoological Survey of India. 



(Plates XXIV— XXVI). 



Contents. 



Introduction 



History 



Probable evolution of the disc of Garra. as represented by a 

 specimens collected in Manipur, Assam 



Skeleton of the mouth-parts 



.\.ir-bladder and associated skeletal structures 



0'a;')-a and Discognathiis 



Synopsis of the Indian and some Extra- Indian species of Garra 

 Part 1. Indian species of Garra 

 Part 2. On some Extra- Indian species of Ga7')-a 



Bibliography 



of 



Page 



634 



6-13 

 646 

 64S 

 649 



651 



676 



683 



INTRODUCTION. 



Among the Indian fresh-water fishes few have greater interest 

 in the study of evolution than those belonging to the genus 

 Garra. Great confusion ha? prevailed in the taxonomy of this 

 genus, parti}- because many of the species exhibit considerable in- 

 dividual variability, and partly because ichthyologists have 

 attempted to apply to them specific standards unsuitable for forms 

 appareirtly still in the process of adaptation to their environment. 

 Scale-counts, number of fin-rays and proportions are all important 

 diagnostic characters in most C5-prinid genera ; but in Garra, at 

 anj- rate, they have much less significance than the structure of 

 certain organs and appliances modified or produced in correlation 

 with the peculiar mode of life adopted, apparently not very long 

 ago, by the members of the genus. Before expressing an opinion 

 as to how this has come about it is necessary that the genus 

 should be investigated as completely as possible ou anatomical 

 and taxonomic lines. This Annandale attempted to do, so far as 

 the taxonomy of the Indian species is concerned, in two recent 

 papers (1919a, b), while Narayan Rao (1920) has still inore recently 

 published a third paper on the same subject and Annandale and 

 I have discussed the generic position of the fish in a fourth 

 (1920). 



