THE PHARYNGEAL TEETH OF FISHES. 133 



worms were found in 16 per cent., principally the Sea-Mouse 

 {Aphrodite aculeata) . Mollusca, chiefly Whelks.* 



Gadus merlangus. The Whiting. 



The horny gill-rakers of the first branchial arch in this 

 fish begin at the angle ; there are none on the epibranchial, 

 they number nineteen on the cerato- and hypo-branchial. The 

 largest ones are nearly the same length as the depth of the gill 

 below them ; the gill-rakers are toothed on their inner face. 

 The gill-rakers on the other arches are tuberculous, and they 

 carry teeth. They fit into each other alternately, and form a 

 close filter. The upper pharyngeal teeth appear as two circular 

 patches of cardiform teeth, consisting actually of three pieces, 

 but the joint of the lower piece hardly shows ; those on each 

 side nearer the middle line are more pronounced than the 

 others. The lower pharyngeal teeth, also cardiform, are in a 

 broad V-shaped patch, separated down the middle by a line of 

 mucous membrane, and here, again, the teeth along the sides 

 nearest the middle line are bigger than the others ; there are 

 two rows of such larger teeth on each side. The food of the 

 Whiting consists of crustaceans, other fish, annelids, and star- 

 fishes. 



Gadus ^glifinus. The Haddock. 



This fish has on the epibranchial two, and on the cerato- 

 hypobranchial of the first branchial arch twenty-three horny 

 gill-rakers, but they are not toothed. The remainder of the 

 gill-rakers are elongated tubercles with minute teeth on them ; 

 they fit more nearly opposite to each other than alternately, 

 thus leaving a large opening for water to pass through to the 

 gills. The upper pharyngeal teeth are cardiform, with the more 

 prominent ones along the tops of the three patches that contain 

 them. The lower pharyngeal teeth are in two patches, forming 

 a narrower V than in the last fish mentioned. The lower apex 

 of the V is separated by a line of mucous membrane, and the 

 larger cardiform teeth on the inner edges of the apex are arranged 

 in clumps at the apex rather than in two rows as in the Whiting. 



* The above percentage of food found in the stomachs of Cods is taken 

 from the information posted up in the " Fisheries Investigations " Cabinet 

 in the Central Hall of the British Museum of Natural History, where speci- 

 mens of some of the food animals are also shown. 



