LIST OF FISH. 



, Huso. — Beards simple, joined together, reaching to the upper 

 lip or beyond it. A. Huso, A. Schypa = A. Dauricus, Fit:. \- 

 Heckle.' 



2. Sturio. — (Formed by uniting Sturio and Helops). Beards 

 simple, roundish, scarcely united. (A. Sturio, A. Gulden- 

 stajdtii, A. stellatus. 



3. Slerleta. — Beards roundish, with small nipple-shaped appen- 

 dages. A. Ruthenus. 



Drs. Fitzinger and Heckle, in their monographs of the genus 

 (Annalen der Wiener Museum der Natury. i. 270, 1836), pro- 

 posed to divide them into two sections, each containing three 

 sub-genera, thus : — 



A. Dorsal-plates in front sloping and behind highest, ending in a 

 point and open up to the point. 



a. The skin covered with small pectinated bony plates. Beard* 



fimbriated. 



1. Under lip continuous. (Lioniscus. — A. glaber). 



2. Under lip not continuous, or a rudiment on each side of 

 the mouth. (Acipenseres. — A. Sinensis, A. Gmelmi, A. 

 Ruthenus, A. Aleutensis, A. maculosus, A. oxyrhynchus. 



b. The skin covered with larger and smaller pectinated bony scales 



and larger stellated bony plates. The beards simple : the 

 under lip not continuous, or simply a rudiment on each side of 

 the mouth. (Helopes. — A. stellatus). 



B. Dorsal-plates on both sides sloping, highest in the middle, end- 



ing in a point. 



a. The skin covered with smaller and larger stellated bony shields. 



Beards simple. Under lip not continuous, or a rudiment on 

 each side of the mouth. (Antacei. — A. Schypa, A. Gulden- 

 staedtii). 



b. Skin chagrined, rough, with bluntish bony knobs. The beards 



simple. Under lip not continuous, or a rudiment only on 

 each side of the mouth. (Sturiones. — A. Heckelii, A. Sturio). 



c. The skin rough, spotted, with pointed bony knobs. The beards 



flattened, riband-shaped. Under lip not continuous, or a rudi- 

 ment on each side of the mouth (Husnnes. — A. brevirostris, 

 A. rubicundus, A. macrostomus, A. Dauricus, A. Huso. 



This arrangement is adopted in this Catalogue. 



B 3 



