XLVIII 



OBSERVATIONS ON THE GENUS PTERASPIS. 



Brit. Assoc, Rep. 1858 {part 2), pp. 82-83. 



In a paper " On Cephalaspis and Pteraspis," recently read before 

 the Geological Society, and published in the ' Quarterly Journal ' for 

 the present year, I endeavoured to prove, — 



1st. That the Cephalaspis Lloydii and Lewisii of the author of the 

 ' Recherches sur les Poissons Fossiles,' subsequently united into a 

 distinct genus, Pteraspis (Kner), were rightly judged by Prof Agassiz 

 to be the remains of fish, and that they are not, as had been imagined 

 by other naturalists, either Crustacean or Molluscan. 



2nd. That, as Prof Agassiz had surmised, they are at once allied 

 to Cephalaspis, and generically distinct from it. 



I grounded these conclusions almost wholly on histological evidence, 

 or that afforded by the microscopic structure of the bodies in question. 

 Not having seen the Ceplialaspis rostratJis of Agassiz, I abstained from 

 offering any opinion with regard to it. 



Since the publication of my paper a great deal of new material 

 has passed into my hands, chiefly by the kindness of the zealous 

 geologists and palaeontologists who reside in and about Ludlow. Messrs. 

 Cocking, Crouch, Harley, Lightbody, Marston, and Salwey, and I 

 have thereby been enabled greatly to extend and confirm my con- 

 clusions with regard to the nature and affinities of these remarkable 

 extinct fishes. A brief note of the results at which I have now arrived 

 will perhaps be interesting to the Section. 



The oblong plates which have hitherto been the only discovered 

 parts of Pteraspis form only a portion of the great shield which covered 



