366 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



loose accessory spines taking the place of the neural spine 

 of that vertebra, and very slightly, by the haemal and neural 

 spines of the second preceding vertebra. 



V. — Anal and Dorsal Interspinous Rays. 



Plate XXIII, Fig. 10; Plate XXIV, Fig. ii. 



The first interhcemal spine (i/is.) of the anal fin is very 

 large and, in cross-section, trilobate. It probably repre- 

 sents the ankylosed first two interhaemals, since to it are ar- 

 ticulated the first two anal spines. The succeeding inter- 

 haemals are very small and weak. 



The same condition is found in the first interneural sfine 

 (ins.), as it bears the first two dorsal spines. It is broad 

 and triangular in outline, and the indications that it is the 

 ankylosed first two elements are move evident. 



VI, — Hyoid Apparatus. 



Plate XXIII, Fig. 8. 



This arch is very typical and nothing need be mentioned 

 except the branchiostegal rays (brr.). They are seven in 

 number, five of them being articulated to the ceratohyol 

 (c/iy.) and two to the efihyol (ephy.). The heads of the 

 first three are not enlarged and are articulated to the lower 

 edge of the ceratohyol, slightly more to the inner than to 

 the outer side of that bone. 



The other four rays have enlarged flattened heads which 

 lie flat against the outer side of the cerato- and epihyols. 



VII. — Branchial Arches. 



Plate XXIV, Fig. 15. 



Two ossified and one cartilaginous basibranchials (bbr.) 

 are present. The first is a short one to which the hyfo- 

 branchiah (hbr.) of the first arch articulate. The second is 

 long and its anterior end is notched to receive the hj^po- 



