STURIONIDEiE. 283 



lining of the gill-openings, the skin surrounding the eye and nostrils being the smoothest. 

 There is a short, smooth groove on the under edge of the tail, between the caudal and anal 

 fins, the use of which is not apparent. 



Fins.— Br. ; P. 43; V. 34 ; D. 52 ; A. 33 ; C. 27/86. 



The pectorals have a greater spread than any of the other fins ; their first ray is very strong 

 and bony, its slender tip, however, being articulated. The ventrals are far back, being nearer 

 to the tip of the tail than to the end of the snout : they have a horizontal position, which, in 

 conjunction with the size of the pectorals, and the position of the mouth, shows that the fish 

 is constructed for taking its pi'ey on or near the bottom of the water. The anal begins as far 

 from the vent as its termination is from the caudal : its middle rays are the longest. The 

 dorsal commences a little posterior to the vent, and terminates a very little anterior to the end 

 of the anal. The portion of the caudal above the tail gradually narrows and disappears short 

 of the point ; its rays are rigid and bony, or spinous with very acute points. The under part 

 of the fin is considerably broader, particularly its anterior lobe ; its margin is sickle-shaped, 

 and its rays are articulated like those of the other fins. The rays of all the fins are very rough. 

 There are seventeen interspinous bones connected with the dorsal, and eleven with the anal. 



Colour. — " Body and top of the head of a hue intermediate between yellowish and bluish- 

 grey, partially iridescent ; shields ash-grey, giving a spotted appearance to the back. Sides 

 silvery-white, with faint vertical bluish-grey bands. Belly white.'" (Gairdner.) 



Intestines. — The oesophagus, or upper part of the stomach, is furnished with seven longi- 

 tudinal rows of crenated papillae ; the rest of the stomach is smooth, with thin coats forming 

 longitudinal folds, except close to the pylorus, where the parietes of the stomach are thick and 

 fleshy, like the gizzard of a fowl. The upper half of the gut, below the pylorus, has its lining 

 finely reticulated, and the remainder is traversed by a spiral membranous valve. A little 

 below the pylorus there is a glandular-looking pancreas which communicates with the gut ; 

 when laid open it appears to consist of honey-combed cells, much resembling the second sto- 

 mach of a ruminating quadruped. The air-bladder communicates with the upper part of the 

 stomach by a pretty large hole. The stomach was filled with the remains of some nearly- 

 digested malloti pacifici, mixed with the light wrack that collects in the eddies of rivers, such 

 as decayed leaves, water-worn pieces of wood, and the exuviae of the larvae of neuropterae. 



The second specimen has a longer and rather more acuminated snout, twelve dorsal shields, 

 forty-two and forty-three lateral ones, and twelve ventral ones on each side. There are also a 

 few roundish plates ranged near the bases of the dorsal shields. In other respects it resembles 

 the preceding ones perfectly. 



2o 



