38 INDIAN FRESH-WATER FISHES. 



The length of the head is from the end of the snout 

 to the hinder edge of the gill cover, in a straight line, 

 not measured round the corner. 



The depth of body is taken at the deepest part, 

 usually just in front of the dorsal fin. 



By " Scales," is meant the number of scales in the 

 length of the body, from the gill cover to the end of 

 the tail. There will usually be found a line of pores 

 running along the side ; this is called the lateral line, 

 and when it runs straight along the middle of the side, 

 the scales may conveniently be counted along it. 

 Sometimes however it is interrupted, or bent suddenly 

 downwards, or wanting altogether. u Tr. " (= trans- 

 verse,) means the number of rows of scales from the 

 back to the belly ; it is as well to count these in three 

 divisions, viz. from the back to the lateral line, from 

 the line to the ventral fin, and from the ventral fin to 

 the centre of the abdomen, thus 7 + 4+3. 



The barbels may be variously placed. 



If belonging to the nostril, they are termed nasal. 



If at the end of the snout, rostral. 



If under the chin, mandibular. 



If on, or at, the corner of the upper jaw, maxillary. 



