ASTEROLEPIS. 



73 



Ctenoptychitjs, Agass. (partim). 

 Nabcodes, Agass. 

 Cosmacanthtts, Agass. 

 Placosteus ?, Agass. 

 Psammolepis ?, Agass. 



Psammosteus ?, Agass. 

 Ctenacanthus, Agass. (partim). 

 Cheieolepis ?, Eichw., non Agass. 

 Micbolepis ?, Eichw. 

 Chelyophobfs, Agass. (partim). 



But though Pander did great service here by pointing out some strange 

 mistakes into which Agassiz had fallen by giving new generic names to fragments 

 which he did not understand, subsequent research has shown that two of the 

 genera contained in the above list, namely, Bothriolepis and Pterichthys, though 

 belonging to the same family, are nevertheless maintainable as distinct from 

 Asterolepis ; while some others, queried, it is true, by Pander himself, are not even 

 referable to the Asterolepidas. An analysis of the table according to the present 

 state of knowledge may, therefore, be interesting. 



To Asterolepis may be referred, besides Chelonichthys, which was withdrawn 

 by Agassiz himself, Odontacanthus, Narcodes. Agassiz also transferred his 

 Gtenoptychius crenatus to " Odontacanthus." As to Chelyophorus, one of Agassiz's 

 species, G. pustulatus, seems to belong to Asterolepis {■= A. concatenata, 

 Eichw aid). 



Bothriolepis, Eichw., is maintainable as a good genus, and with it are certainly 

 synonymous Pamphractus, Homothorax, Placothorax, — possibly also Cosmacanthus, 

 though this is a most undeterminable fragment. Glyptosteus was withdrawn by 

 Agassiz himself in favour of Bothriolepis. 



Pterichthys, Agass., though very close to Asterolepis, is nevertheless retainable 

 as distinct. 



Psammosteus, Agass. (including Placosteus and Psammolepis, names withdrawn 

 by Agassiz), has nothing to do with the Asterolepidse, and the plates here included 

 are probably Selachian. To a similar category belongs Gtenacanthus semdatus, 

 Agass., which Mr. Smith Woodward quotes as a synonym of Psammosteus 

 mseandrinus. With regard to Eichwald's Microlepis, and the species splendens and 

 unilateralis, which he referred to Cheirolepis, they were considered by Agassiz as 

 well as Pander to be referable to Psammosteus. By Mr. Smith Woodward they 

 are designated as "indeterminable." 



Of course if Asterolepis were identical with, or even allied to Pterichthys, the 

 name could no longer be applied to Hugh Miller's large fish from Orkney and 

 Caithness, which was correctly assigned by Pander to Asmuss's genus Homosteus, 

 after being duly deprived of the " teeth of Dendrodus and the scales of Glyptolepis," 

 with which Miller, misled by Agassiz, who classed "Asterolepis" among his 

 " Coelacanthi," had mistakenly endowed it. 



Naturally Pander's views did not meet with immediate acceptance in this 

 country, where people were loth to abandon or change names for British fossils 



