PISCES. 73 



We unite three genera here, of which perhaps each might, with 

 as much propriety, be placed in a distinct family, as MUELLER forms 

 of Lepidosteus and Polypterus two distinct families. Amia L. ought 

 also to be joined with these genera, as has been shewn by VOGT and 

 MUELLER. Yet Amia can be brought into no nearer connexion 

 either with Lepidosteus or with Polypterus. Hence for this genus 

 also a distinct family would be required. In the arrangement of 

 CUVIER these three genera, with many other osseous fishes, are 

 placed in the family of the Clupeacii, amongst the Malacopterygii 

 abdominales. 



The family of the Sauroidei of AGASSIZ contains a great number of 

 extinct genera, which are no longer met with after the Jura-formation, as 

 Diplopterus, Pygopterus, Saurichtkys, &c. More numerous still are those 

 Ganolepidoti which are referred by AGASSIZ to another family, quite extinct, 

 that of the Lepidoides, to which the genus Palceoniscus belongs 1 ; these are 

 distinguished commonly by small teeth. A third family of the Ganolepi- 

 doti, characterised by flat, round teeth arranged in many rows, that of the 

 Pycnodontes, is also entirely extinct. To this is referred the genus Placodus 

 AGASS., with very large flat teeth in the palate, of which the remains are 

 found in the MuscJielTcalTc. See AGASSIZ Poiss. foss. II. 2, pp. 217 222, 

 PI. 70. The limits of this Hand-book do not permit us to enter into further 

 particulars concerning these extinct genera of fishes. 



Lepidosteus AGASSIZ (Lepisosteus LACEP.). Jaws produced, 

 narrow. Hard osseous scales, rhombic, arranged in oblique rows 

 descending backwards from the back towards the belly. Branchio- 

 stegous membrane with three rays. Dorsal fin small, remote 

 towards the tail, placed above the anal or a little behind it. First 

 ray of dorsal fin, of anal, of pectoral and ventral fins and the 

 external rays of caudal fin, covered with aculeate imbricate scales, 

 serrate. Vertebral column produced in the direction of the superior 

 margin of caudal fin. 



Sp. Lepidosteus osseus LAC., Esox osseus L., Lepidosteus Bison DE KAY, 

 BLOCH Ichth. Tab. 390, AGASSIZ Poiss. foss. n. Tab. A (except fig. of 

 skeleton) ; Lepidosteus spatula LAC. Poiss. V. PL 6. fig. 2 ; with a flat 

 head and shorter jaws ; this species becomes 7 feet long. RAFINESQUE 



1 In the Kupferschiefer a species of it occurs which, in honour of the Geologist who 

 illustrated this formation so greatly by his investigations, has been named Palceonis- 

 cum Frieslebenense (BLAINVILLE Nouv. Diet. d'Hist. nat., nouv. e"dit. xxvii. p. 320), or 

 Palceoniscus Frieslebeni AGASS. CUVIER had already observed the resemblance of 

 these fossil fishes to Lepidosteus and Acipenser, Reck. s. I. Ossern. foss., 3ieme ed. V. 2, 

 PP- 3<>7> 3o8. 



