86 
THE PRESENCE OF A SESAMOID ARTICULAR 
IN SOME OF THE COMMON FISHES. 
By B. STORROW. 
Whilst making a preparation of the skull of a ling in March, 
1909, a small flat irregularly shaped bone, a sesamoid articular, was 
found internal to the articular and in close relation to Meckel’s 
cartilage. Previous to this date, skulls of the cod, haddock and 
whiting had been prepared, but this bone was not noticed. This 
was because hot water was used for cleaning purposes, and the bone 
in these heads, being small and loosely attached to the articular, 
comes away easily with Meckel’s cartilage. 
Dr. Ridewood, whom I have to thank for the identification of 
this bone, describes the sesamoid articular on pages 71 and 72 of 
the Proceedings of the Zoological Society for 1904, and in his paper 
on the Cranial Osteology of the Clupeoid Fishes, December, 1904, 
notes its presence in some of the skulls he examined. 
In 1909, during August, September and October, I examined 
and prepared skulls, or parts of skulls, of the cod, haddock, whiting, 
hake, ling, torsk, cat-fish, opali and plaice, and in every case the 
sesamoid articular was present. In the opah it is placed above and 
behind the proximal end of Meckel’s cartilage ; in the other fishes 
named it is developed above and around Meckel’s cartilage. The 
hone, in the heads examined, varies in size according to its devlop- 
ment above Meckel’s cartilage. In the ling, cat-fish and opah, it is 
fairly large, yet less than the angular, except in the cat-fish where 
it is slightly larger ; in the others, especially the plaice, it is very 
small, and is most easily found by dissecting out the levator muscle 
of the mandible, in the tendon of which it is developed. A rough 
examination has also been made of the lower jaw of the horse 
mackerel, and a small pointed bone was found internal to the 
articular, but a further examination is necessary before stating a 
sesamoid articular for this fish. 
The preparations made are now in the laboratory, and had it 
not been for the kindly help and advice given by Professor Meek I 
should not have been able to deal with them as I have done. 
To Mr. Wood, a member of the Coast Club, I am indebted for 
the photograph illustrating this short paper. 
In June of this year, a sesamoid articular was found whilst 
preparing the skull of a northern cat-fish ( Anarrhichas latifrons) 
