4 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 122 



Head length (HL): Taken from the mid tip of the upper lip to the 

 posteriormost point reached by the fleshy margin of the opercle, 

 exclusive of the branchiostegal membrane. 



Orbital length (OL): The horizontal diameter between the fleshy 

 rims of the orbit. This character decreases strikingly in relative 

 size with increase in SL. The species vary noticeably from each 

 other. I have attempted to illustrate this variation in table 3. 



Supraorbital cirrus length (OCL): The distance from the lateral 

 point where the base of the cirrus joins the conjunctiva of the eye 

 to the most distal point reached by the cirrus (the cirrus thus measured 

 is the main, or longest, supraorbital cirrus; other cirri on its margins 

 are branches). This measurement and the next are taken while 

 the cirri are wet (the cirri shrink considerably when dried even 

 slightly). 



Nuchal cirrus length (NCL): The longest measurement from the 

 midbase of the cirrus to the distalmost tip of the cirrus. In those 

 specimens where the nuchal cirri arise on each side from two separate 

 bases, the measurement was made from that base supporting the 

 longest cirrus. 



Third dorsal spine length (DS3): From the proximalmost point of 

 the posterior axil, formed by the spine with the body contour, to the 

 distal tip of the spine, disregarding the normal curvature of the spine. 



Thirteenth dorsal spine length (DS13) ; Similar to DS3. 



First dorsal ray length (DRl) : Similar to DS3. 



Pectoral fin length (PECL) : The length of the longest ray. 



Pelvic fin length (PELL) : Taken from the internal, proximalmost 

 point of attachment of the fin to the body to the tip of the longest 

 ray. 



Caudal fin length (CL) : The length of the longest ray. 



Humeral blotch length (HBL) : The longest horizontal distance 

 between the anterior and posterior margins of this marking. Where 

 this blotch is composed of two portions, the measurement is taken of 

 the posterior marking. 



Counts. — All counts of bilaterally paired structures were made on 

 the left side of each specimen when possible. Where population or 

 growth differences warrant it, I have given frequency distribution 

 tables of the variation in particular counts. For the sake of con- 

 venience of species comparison I have also given summary tables of 

 fin ray, vertebrae, gill-raker and pseudobranchial filament counts in 

 which all the counts for a given character for a given species have 

 been combined (tables 1 and 2). 



Dorsal fin spines: A count of the bases of the unsegmented elements. 

 The posteriormost spine (usually the 13th) is frequently visible only 

 in skeletal preparations or on radiographs. This element when not 



