iii the Province of Ceara, in the North of Brazil. 83 



tion by Mr Bowman, I have recognised seven distinct species, 

 all new, but which appear to me to identify not the less the 

 deposit in which they are found as belonging to the chalk-for- 

 mation, and that because of the simultaneous occurrence of 

 Ganoid, Ctenoid, and Cycloid fishes. 



The two Ganoids which I have recognised, belong to two 

 genera already characterized in my Becherches sur les Pois- 

 sotis Fossiles. They are 



1. An Aspidorhynchus, which I have named A. Comptoni ; 

 allied to the A. ductus of the Kentish chalk, but which differs 

 from it by its scales being more rugose. I have dedicated it 

 to the Marquis of Northampton, who communicated the first 

 specimens to me. 



2. A Lepidotus, which I shall name L. temtiurus, charac- 

 terized by the numerous articulations of the rays and of its fins. 

 The species of lepidotus met with in the chalk of Kent has 

 more elongated scales than those of the L. temtiurus. 



The Ctenoids are three in number, but they belong to one 

 genus, of which I am not acquainted with a living species. 

 Its characters are very remarkable ; and it is a combination of 

 features borrowed from several types, afterwards distinct. One 

 dorsal scaly fin, without spinous rays, combined with ventral 

 fins occupying the middle of the abdomen, and pectinated 

 scales, form, certainly, a very peculiar assemblage of characters. 

 I have named this genus Phacolepis, and have distinguished 

 three species. 



1. Phacolepis Brama. Broad: second posterior suborbitary 

 narrower than the superior. 



2. Phacolepis buccalis. Elongated ; the two posterior sub- 

 orbitaries of equal size, and elongated. 



3. Phacolepis latus. Short, broad ; the two posterior sub- 

 orbitaries equally short, and of the same breadth. 



The Cycloids belong to two extinct genera. 



1. Cladocyclus, covered by very large scales, higher than they 

 are long, marked with pores and lobed furrows, diverging to- 

 wards the posterior edge. Small conical teeth. There is only one 

 species, CI. (iardneri, of very great size, which I have dedicated 

 to the zealous traveller to whom the discovery is due. The 

 scale from the Kentish chalk, which 1 have figured in my work 



