188 THE ZOOLOGIST. 



mately there are thirty-five to the inch. There are eleven on 

 the first epibranchial. Long gill-rakers only grow on the upper 

 surfaces of the first four arches ; they stand up and lean across 

 the gill-slits. Those on the first arch stand up and keep all food 

 inside the mouth, those on the upper surfaces of the second, 

 third, and fourth arches close the gill-slits next outside of 

 them. The fourth gill-slit is closed by small gill-rakers growing 

 from the inside of the fourth and outer side of the fifth branchial 

 arches. The gill-rakers on the second, third, and fourth arches 



Fig. III. 



POLYPTERUS CLUPEA TeTRODON 



SENEGALUS. FINTA. RETICULARIS. 



are long and fine ; similar ones grow on their epibranchials. 

 The whole forms an excellent filtering apparatus, which, con- 

 sidering the fine nature of the Herring's food, is essential. Here, 

 again, reference may be made to the Fisheries Investigation 

 cabinet in the hall of the British Museum of Natural History, 

 where some of the minute organisms on which the Herrings 

 subsist are displayed. 



Clupea ilisha, called the " Pulla " in Scinde and the " Hilsa " 

 at Calcutta, is much esteemed for the table. It has on the first 

 branchial arch from the angle to the end of j the hypobranchial 



