COMPAGNO and SPRINGER; NEW GENUS OF CARCHARHINID SHARKS 



Table 2. — Proportional measurements of lago omanensis expressed as percentages of 

 total lengths; measurement method follows Bigelow and Schroeder (1948). 



' In 4 moles or 6 females. 



Mouth width about two-thirds of width of 

 head at mouth corners; edge of lower jaw 

 convex. 



Teeth show modest gradient heterodonty; 

 from symphysis to mouth corner teeth become 

 lower relative to their root lengths; tooth size 

 changes also along this gradient, starting from 

 small to largest in about four rows from medials 

 and gradually becoming smaller towards ends 

 of dental band. 



Body moderately slender, trunk rather high 

 anteriorly, almost humped above pectorals, 

 sloping posteriorly to pelvics and caudal origins; 

 caudal peduncle long, slender, subquadrate in 

 cross section, a weak postdorsal ridge extending 

 medially from just after second dorsal to caudal 

 origin; an ill-defined predorsal ridge extending 

 for a shoi't distance anterior to first dorsal fin; 

 distance from snout tip to cloaca somewhat less 

 than distance from cloaca to caudal tip. 



Dermal denticles small, those of dorsal sur- 

 face below first dorsal fin base 0.04 to 0.08% 

 of total length in two specimens, 0.15 to 0.35 mm 

 in 457-mm female; anterior edges and posterior 

 cusps of adjacent denticles somewhat overlap- 

 ping, skin visible between denticles; denticles 

 transparent, without pigment and more or less 

 invisible when wet; chromatophores of skin be- 

 tween denticle bases visible through denticles; 

 bases of denticles short, subquadrate, with rel- 

 atively short pedicels; medial ridge of crown 

 not subdivided longitudinally (Figure 6) ; con- 

 cave depression present on either side of medial 

 ridge, with its lateral boundary deflected slightly 

 outward to form an incipient lateral ridge that 

 may or may not terminate in a short lateral cusp; 

 lateral cusps generally absent from denticles of 

 caudal and ventral surfaces ; denticles below first 

 dorsal becoming wider relative to their lengths 

 with increase in specimen size; small denticles 



621 



