PISCES. 71 



OKDER V. Sturiones (Chondrostei MUELL.). 



Skeleton cartilaginous. Lower jaw attached to the cranium by 

 means of a suspensory formed of three parts. Bays of branchioste- 

 gous membrane none. Tail asymmetrical, with fin adhering be- 

 neath the spine of back. 



Family VII. Sturianes. (Characters of the order those also of 

 the single family.) 



Adpenser L. Body with an armour of osseous scutes, disposed 

 in five longitudinal rows. Head produced beyond the mouth into 

 a triangular apex, flat below. Cirri in front of the mouth inferior 

 and edentulous. 



Scapliirhynchus HECKEL. Temporal foramina none. Body behind 

 the pectoral fins covered everywhere with large scales, depressed. 



Sp. Scaphirhynchus Rafinesquii HECKEL, Annalen des Wiener Museums I, 

 Wien, 1836, pp. 76 78, Tab. vin ; North America, in the Ohio and Mis- 

 sissipi ; attains a length of 2' 3'. 



Adpenser L. Temporal foramina. Hows of scutes extending as 

 far as tail, skin naked in the interstices, rough with small dispersed 

 squanmles. 



Sp. Adpenser sturio L., BLOCH, Tab. 88, BRANDT u. RATZEB. Mediz. Zool. 

 u. Tab. 3, fig. i, the sturgeon ; attains a length of 6 10 feet ; the dorsal 

 scutes are highest in the middle ; the filaments beneath the head are with- 

 out appendages and terminate in a point. In other species they are flat 

 like a band (Adpenser huso~L., BLOCH Ichth. Tab. 129, BRANDT u. RATZEB. 

 1. 1. Tab. I a, Suppl. fig. i), or with small appendages like fringes. 



The sturgeons live in the seas of the northern hemisphere, and from 

 thence ascend different rivers. They attain a remarkable size (Adpenser 

 huso, ex. gr. 25 feet). Most of the species belong to Eastern Europe and 

 Western Asia (Black Sea, Caspian Sea). From the roe caviar is prepared, 

 from the swimming-bladder isinglass. To prepare the last (Hausenblase 

 from Hausen, the German name of Huso), of which the best kind comes from 

 Astracan, the swimming-bladder is laid in warm water, cut open, washed 

 and exposed to the air, so that the internal silvery membrane lies upper- 

 most ; this having been removed by rubbing, the external membrane is 

 dried. 



Compare on this genus BRANDT u. RATZEBURG Mediz. Zool. n. s. i 30, 

 s. 349 355, and FITZINGER u. HECKEL Annalen des Wiener Museums, i. 

 s. 261 326, Tab. 25 30. In some species there are two rows of ven- 

 tral scutes, little developed, or in old individuals they are very flat (Adp. 

 ruthenus L.), on which are founded the statements of some writers that 

 there are sturgeons with only three rows of scutes. 



