FISHES OF THE FAMILY SIGANID^E. 2 1 J 



between the prefrontal and the ethmoid. The vomer is branched 

 or Y-shaped and toothless. The opisthotic is present in its usual 

 position covering the suture between the exoccipital and the 

 pterotic. The parietal is entirely absent, and the frontal and 

 epiotic bound the supraoccipital. 1 The remaining cranial ele- 

 ments are typical of the majority of the spiny-rayed fishes and 

 are well shown in the accompanying drawings. 



The post-temporal is forked and though the lower fork is very 

 short it is continued by a ligament and joined to the opisthotic in 

 the usual way so that the post-temporal stands away from the 

 cranium as it does when the lower fork is long. The superior 

 fork is rather broadly but not firmly joined to the epiotic. A 

 couple of tunneled dermal bones, the supratemporals, are present 

 on each side of the cranium in front of the post-temporal. The 

 hypercoracoid foramen is large and is directly in the center of the 

 bone. The actinosts are moderately long and somewhat con- 

 stricted in the middle ; three of them join the hypercoracoid and 

 one the hypocoracoid. The upper pectoral ray works directly 

 on the edge of the hypercoracoid. The postclavicle is a long, 

 slender, curved ray of bone composed of an upper and a lower 

 element. The other shoulder girdle elements are typically per- 

 coid in size, shape, and arrangement. 



The lower part of the pelvic girdle extends forward as a long 

 roughened plate just under the skin of the breast. From the 

 upper surface of this plate the girdle is developed vertically up- 

 ward, and meeting its opposite fellow at the upper edge, which 

 is inclined towards it, incloses a chamber between. Anteriorly a 

 long spine is sent forward from the upper edge of the girdle to 

 between the clavicles. Backward over the base of the ventral 

 fin a triangular spine is developed. The posterior or inner ven- 

 tral fin spine is attached to the lower surface of this triangular 

 pelvic spine — the anterior or outer ventral fin spine is attached 

 to the base or posterior end of the breast plate. Some space is 

 left between the ventral spines in which the three ventral rays 

 are placed with their bases close together nearer the posterior 

 ventral spine than the anterior. 



1 Several crania of different sizes (the smallest from a specimen 7 cm. in length) 

 were prepared and examined on both the inner and outer surfaces, but no trace of the: 

 parietal was found. 



