50 Proceedings of the Royal Physical Society. 



another on the mode of articulation of the anterior median 

 dorsal plate. 



But Agassiz's work, in which he classified '' Asterolepis " 

 among his " Ccnelacantlii," a group generally equal to the 

 Cjcliferous Crossopterygii of more recent times, was the 

 means of drawing Hugh Miller into mistakes of much 

 greater importance than mere nomenclature. Accordingly, 

 as Pander j^ointed out. Miller attributed to his Asterolepis 

 " the teeth of Bcndrodus and the scales of Glytolcpis" and 

 made a very formidable creature out of it, ten to thirteen 

 feet in length ; indeed, referring one of the large Eussian 

 plates {Heterosteus, Asmuss) to the same genus, he calculated 

 a length of eighteen to twenty-three feet for the entire fish. 

 And his non-recognition of the true affinities of the creature 

 led also to other mistakes in the identification of bones, to 

 which allusion will be made in due course. 



By Asmuss Homosteus and Heterosteus were placed in a 

 family by themselves, Chelonichthyda, in a somewhat hetero- 

 geneous group of "Ganoidea loricata," tlie other families herein 

 included being Spatularida, Acipenserida, Coccosteidp. Pter- 

 ichthyda, and Cephalaspida. As regards Homosteus, though, 

 as Pander remarks, it is wonderful how, without knowledge 

 of Hugh Miller's drawings or description, he was able to fit 

 together the isolated plates at his disposal, yet, unacquainted 

 with the orbits, he supposed the cuirass to belong exclusively 

 to the body, and also entirely reversed its position on the 

 animal. 



Pander, however, classified Homosteus in M'Coy's group of 

 Placodermata, and rightly gave it a place immediately after 

 Coccosteus, interpreting as its median dorsal plate the one 

 considered by Hugh Miller to be a " hyoid," and supposed by 

 him to occupy a place between the rami of the jaws. This 

 supposed hyoid plate was known to Hugh Miller only in an 

 isolated form, but it fell to the lot of the late Mr John Miller, 

 of Thurso, to record a specimen in which it occurred' in its 

 natural position on the back behind the head, and so with 

 absolute certainty to confirm Pander's view of the case. Mr 

 Johu Miller's collection having some years ago passed into 

 the possession of the Museum of Science and Art, Edin- 



