270 M. K. F. Kessler on a remarkable 



called spiracles are wanting. Down the body there are five 

 rows of scutes, of which the upper (dorsal) row ends at the 

 commencement of the dorsal fin, and the abdominal rows at the 

 base of the ventral fins, the lateral rows extending to the end 

 of the tail. The tail, behind the dorsal and anal fins, is slightly- 

 flattened and completely covered with osseous scutes ; the end 

 of the tail terminates in a more or less long filament. 



Specific Characters of Scaphirhynchus Fedtschenkoi. — The 

 length of the spade-like snout is subject to great variation, but 

 never less than three fourths of the whole length of the head, 

 or less than one fourth of the length of the whole body to the 

 base of the caudal fin ; the barbels are not fringed, placed in a 

 curved line, and are distant further from the end of the snout 

 than from the opening of the mouth ; the diameter of the little 

 eyes does not exceed 2 millimetres ; the distance from the 

 anus to the commencement of the anal fin is a little greater 

 than that from the end of the anal fin to the beginning of the 

 caudal. 



Detailed description. — The length of the snout, together 

 with that of the whole head, is subject to very great variation. 

 In some of those specimens which might be called short- 

 snouted the length of the head consists of a little more than 

 one third of the length of the whole body to the base of the 

 caudal ;. in others with long snouts the length of the head is as 

 much as four ninths of the length of the whole body. The 

 breadth of the head at the gill-openings is contained in the 

 length of the body (without caudal) from seven to eight times, 

 • the breadth of the basal part of the snout being a little greater 

 than that of the head at that point. The head is flat-convex 

 above, quite flat below. The snout has the shape of a more 

 or less long spade, which from the centre to the margins gra- 

 dually becomes thinner, and from the base to the end both 

 thinner and narrower. The end of the snout is sharp, 

 rounded, and the margins are rather soft, in consequence 

 of which they slightly bend inwards in dried specimens, 

 giving to the snout the appearance of a shallow gutter. The 

 posterior ends of the margins of the snout form two bony pro- 

 minences or hooks, directed towards the gill-covers. A little 

 in front from these hooks is the widest part of the snout • and 

 behind them, close to the gill-covers, the breadth of the head 

 is a little smaller than that of the snout. 



The whole upper surface of the head is covered with shields, 

 which, however, are less prominent and less distinct than in 

 the American species — the less so, as they are covered with a 

 thick layer of skin forming many longitudinal folds. There 

 are seven principal shields — one occipital, two parietal s, two 



