92 Cockerell and Moore — Nature of Teeth in Ctenoid Scales. 



vergence and coalescence of those immediately adjacent. The 

 few genuine radii in this scale are between the teeth, and in the 

 figure one is seen crossing the circuli obliquely. 



The Lutianid, Neomxnis griseusO^-), and the Hpemulid, Aniso- 



Fig. 2. 

 Scale of Anisotremus rirginicus, showing connection of vertical 

 circuli witli teeth (left) and connection of lateral with apical 

 cixculi (right). 



tremus virginicKS (L.), (scales of l)oth from Tampa, Florida, 

 kindly sent by Dr. S. Graenicher) illustrate the same thing in 

 a different way. The jointed lines radiating at the apex are not 

 radii, but modified circuli. Their connection with the lateral 

 circuli can be distinctly made out as is shown in our figures. 



Fig. ;i. 

 Portion of scale of Citharidium ansorgii, showing 

 a lateral apical tooth, A' R. on radius, other 

 ma risings circuli. 



It follows from the above theory that a scale with completely 

 transverse apical circuli, such as that of Argyrosomus, can not 

 be and can not l)ecome ctenoid. The reason why there are no 

 ctenoid Cyprinid scales seems to be, that the group has advanced 



