which it extends to somewhere between the level of about 

 one-third to three-fourths down the pectoral fin base, the 

 slit being especially short in Halimochirurgus alcocki 

 and Macrorhamphosodes uradoi. 



The length of the pseudobranch, more or less corre- 

 lated with its number of lamellae, varies from especially 

 long, as in Triacanthodes, in which it extends below the 

 level of the lower edge of the pectoral fin base, to short, as 

 in Mephisto, Bathyphylax, and Macrorhamphosodes, in 

 which it extends to the level of the upper edge of the pec- 

 toral fin base, with the other genera variously in- 

 termediate. 



The greatest depth of the body in adults of Triacan- 

 thodes, Mephisto, Paratriacanthodes, Johnsonina, and 





