20 



THE SESAMOID ARTICULAR 



Cyprinus carpio, Leuciscus bicolor, Semotilus atromaculatus, Ptycho- 

 cheilus oregonensis, Orthodon microlepidotus, Pogonichthys 

 macrolepidotus. 



The sesamoid articular is more slender than in Deltistes et. al., more 

 closely associated with Meckel's cartilage, which is much more slender, 

 and it is lower in position, being remote from the upper margin of the 



an 



Fig. 8. LEUCISCUS BICOLOR 



\, angular; d, dentary; epr, endosteal process; me, Meckel's cartilage; 

 sa, sesamoid articular. 



articular. It is a large flat bone lying closely against the articular, and 

 articulated along its lower edge with the endosteal process and with 

 Meckel's cartilage, being concave to fit over them. There is a prominent 

 tubercle of bone above its middle to which a stout tendon is attached. 



Misgurnus anguillicaudus. 



In this form I fail to find a separate sesamoid articular, though a 

 tendon is attached to the middle of the articular about in the typical place 

 for one. The inner part of the articular is broken up into a lace-like plate 

 which seems to be an integral part of it. 



THE SILUROIDS. 

 Silurus glanis. 



The sesamoid articular is smaller than in the other siluroids examined. 

 It is situated on the upper inner edge of Meckel's cartilage, and a small 



