and Systematic Position of Cheirolepis. 239 
correctly identified by him ; but he failed to find the branchio- 
stegal rays and the two sizes of teeth described by Agassiz. 
But it is specially worthy of note that Pander seems to have 
been struck by the considerable resemblance which certain 
bones of the head of Chetrolepis bore to those shown in 
Quenstedt’s drawing of the head of Paleoniscus islebiensis 
in the ‘ Handbuch der Petrefactenkunde.’ 
The question of the systematic position of Chetrolepis was 
next discussed by Prof. Huxley*. Unfortunately, the material 
at his disposal at the time he wrote did not afford him the 
opportunity of making much advance on what had been 
already done by Pander, though assuredly he was on the 
right track. He accepted the institution by Pander of a 
distinct family of Checrolepind; and as regards the suborder 
in which this family should be included, he considered that 
it ought “ perhaps to be regarded as the earliest known form 
of the great suborder of Lepidosteide.” The single short 
dorsal fin, the absence of jugular plates, and the non-lobate 
character of the paired fins were points justly considered by 
Prof. Huxley as excluding Chetrolepis from the Crosso- 
pterygide. 
In 1867, however, Mr. Powrie published a paper t in which 
he questioned the accuracy of the data on which Prof. Huxley’s 
opinions were founded. Cherrolepis, Mr. Powrie affirmed, 
does possess two large principal jugular plates ; and the struc- 
tures described by Agassiz as branchiostegal rays, but not 
seen by Pander or Huxley, ‘“ correspond to the lateral jugular 
plates not uncommon in Ganoid fishes.” Although in this 
paper Mr. Powrie thinks that Prof. Huxley’s objections to 
Chetrolepis being a Crossopterygian are so far negatived, he 
nevertheless does not positively indicate the systematic posi- 
tion in which he thinks it ought to be placed. 
In Dr. Liitken’s essay on the Classification and Limits of 
the Ganoids{, Checrolepis is placed, somewhat hesitatingly, 
among the Lepidosteids, Mr. Powrie’s jugular plates proving 
to him rather a stumbling-block. In the English abstract of 
this elaborate paper, Dr. Liitken states the absence of jugular 
plates to be one of the characteristics of the group of Lepi- 
dosteidee, ‘with the sole exception of Chedrolepis, the only 
Devonian fish of the whole series which indicates by its 
gular plates a certain relationship to the contemporaneous 
Polypteride ’§. Again, in the full German edition published 
* Dec. Geol. Survey, x. (1861) pp. 38-40. 
+ Geol. Magazine, 1v. 1867; pp. 147-152. 
{ Vidensk. Meddelelser nat. For. Kjébenhavn, 1868. 
§ Ann. & Mag. Nat. Hist. 4th ser. vii. p. 331. 
LT 
