REVISION OF CARCHARHINID SHARK GENERA — SPRINGER 565 



caudal lobe faded into the dorsal body contour. The point is usually 

 close to the posterior end of the upper precaudal pit. A line was 

 extended ventrally, and, using the triangle, I measured the distance to 

 this line. 



lower caudal origin : This was obtained in a way similar to that 

 used for the upper caudal origin except that it was necessary only to 

 mark the origin. 



Distance between the inner corners of the nostrils: Measured as 

 the least distance between the two nostrils. 



Mouth width: The distance between the corners of the mouth. 



Mouth length: The distance from the tip of the lower jaw to the 

 midpoint of a line connecting the corners of the mouth. 



Upper labial furrow length: The distance from the anterior end of 

 the upper furrow to the posterior tip of the fold formed by the furrow. 



Lower labial furrow length: The distance from the anterior end of 

 the lower furrow to the posterior tip of the fold formed by the upper 

 furrow. 



Gill-opening length: Measured by placing the divider points at the 

 dorsal and ventral points of junction of the gill-opening with the body. 



Eye diameter: The length of the horizontal diameter of the rim 

 of the orbit. 



First dorsal fin, second dorsal fin, and anal fin — ■ 



total length: Measured from the origin to the tip of the posterior 

 margin of the fin. This measurement usually is slightly smaller 

 than the sum of the next two measurements because of the difficulty 

 of determining the exact anterior margin of the axil. 



length of base: Measured from the origin to the axil. The 

 latter point is determined by raising the posterior margin of the fin 

 and placing one point of the dividers on the most posterior extension 

 of the base. This point is somewhat posterior to the anteriorly 

 extending furrow of the posterior margin. 



length of posterior margin: The distance from the axil to the 

 posterior tip of the fin. 



height: A measurement perpendicular to the base of the fin 

 made by placing one point of the dividers at the axil and the other 

 at an imaginary point on the level of the tip of the anterior margin 

 of the fin. 



Pectoral and pelvic fins — ■ 



inner corner: The angle formed by the junction of the distal 

 and posterior margins of the fin. 



length of base: Measured in same manner as the vertical fins 

 above. 



length of anterior margin: Measured as the length of a straight 

 line from the origin to the most distal point on the anterior margin 

 of the fin. 



