ACTPENSER STELLATUS. 395 



termination of which becomes narrower, and extends beyond the barbels. 

 The inner pair of barbels is slightly posterior to the outer pair. They do not 

 extend nearly so far back as the mouth (Fig-. 185). 



The whole under part of the snout, on each side of the median ridge, is 

 covered with large pores for as far back as the barbels reach. 



The somewhat large mouth is situate below and rather behind the eyes. 

 It is somewhat transverse, and is margined in front by a small cartilaginous 

 fold of the lips, which is slightly notched laterally. The eyes are small and 

 oval ; the right eye is about one-seventh larger than the left, and the breadth 

 of the frontal interspace is equal to five times its diameter. The upper nasal 

 aperture is much smaller than the lower narine. 



The shields of the longitudinal rows are well developed, those of the dorsal 

 row are strong, have a heart- or lozenge-shaped base, and a strongly-raised 

 point, which is not the hindermost part of the keel. They vary in number from 

 twelve to sixteen. The first is less firmly united to the back of the head than usual. 

 The two following are the least elevated. The sixth to eighth are highest 

 all have the characteristic radial ribbing. The lateral shields are lozenge- 

 shaped, with serrated edges, and are often separated by interspaces equal to the 

 length of the base of the shield. They vary in number from thirty to forty. 



The ventral shields are ten to twelve in number, they are lozenge-shaped, 

 and similar to the dorsal shields, only much smaller. There are one to three 

 similar shields between the anal fin and vent, but there are none of these small 

 shields behind the dorsal fin. The shields at the sides of the head, which support 

 the shoulder girdle, are regarded by Professor Parker as supra-temporal. They are 

 large and triangular, coarsely radiated, with a slight keel. Between the rows 

 of shields the skin is thickly covered with small denticulated bony scales, which 

 are irregularly placed. They are most dense behind the pectoral fin, and are 

 largest between the dorsal and lateral shields, where they have a star shape, 

 and notched border. On the belly their shape and arrangement are much 

 more regular, and in the middle line, from the throat to the vent, there is 

 usually a sharply-defined median row, especially in the male. 



There is frequently a similar row of star-like scales on each side of the 

 ventral shields. All the fins are somewhat small. The pectoral is only one- 

 fifth longer than the diameter of the body. The anal, as usual, is opposite 

 the hinder part of the dorsal. The upper lobe of the caudal is slender and 

 scythe-shaped. The upper caudal lobe is much larger than the lower lobe, and 

 both are pointed. 



The coloxir of the back is a reddish-brown, or, sometimes, bluish-black. 

 The sides and belly are white, but the under side of the snout is flesh-coloured. 

 .The shields arc dirty white. The iris is yellow or silvery. 



