216 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



character, however, Sir Philip Egerton and Professor Owen inform 

 me, is only of partial application ; the family of Cephalaspides he does 

 not cite, but in Coccosteus, tlie sole form of Old Red fishes in which 

 vertical fins have been observed, the distance between them is con- 

 siderable. In the Dipterians, Dipteriis has these organs very close, 

 but in Diplopterus and Osteolepis they have considerable intervals 

 between them. Diplopterus moreover occurs in the coal-measures. 

 In the Ccelacanths the fins of Glyptolepis are very near each other, 

 but this family runs into the chalk. In the Acanthodians the fins 

 are quite distinct, and Acanthodes is found in the coal-measures. 

 There are also recent fishes with their vertical fins quite as little 

 distinct as in the most exaggerated of the Old Red. Neither is the 

 heterocerque tail a character peculiar to the fishes of the Old Red, 

 for all the fishes older than the lias have this form, as have the 

 Sturgeons of the present day ; and it is perhaps more important to 

 find, that certain highly characteristic genera of the Old Red, for 

 example, Pterichthys, Pampliractus and Coccosteus, did not possess 

 the heterocercal tail. 



Another character, viz. the flattened form of head, is not peculiar 

 to the Old Red, for the Siluridm and other recent fishes have this 

 character equally prominent. Then the non-development of the 

 vertebral column is found in the Sturgeon, Lamprey and other recent 

 fishes. Persons seeking for support to the theory of progressive de- 

 velopment might, on a hasty perusal of this work, find sentences in 

 favour of their views ; but the above facts are irreconcilable with 

 the theory as ordinarily promulgated, and it would be a perversion 

 of M. Agassiz's undoubted opinions to quote detached sentences 

 from his writings in support of that doctrine. They will find for 

 instance, at p. 23, a rectification of the error committed by the in- 

 genious Hugh Miller, in describing the jaws of the Coccosteus as 

 being vertical, like those of Crustacea, and thence inferring that " it 

 seems to form a connecting link between two orders of existences;" 

 M. Agassiz having proved that they are horizontal, and move verti- 

 cally, as in other true fishes. Then there are four species of Sharks 

 of the Cestracion division in the Devonian rocks of Russia, and the 

 squaloid fishes of the present day offer the highest organization of 

 the brain and of the generative organs, and make in these respects 

 the nearest approach to the higher vertebrate classes. 



The work of Professor Owen on the fossil remains of Mammalia 

 and Birds found in the British Islands, which has been for some time 

 in course of publication, is now completed, the concluding part having 

 been published within the last i'ew days. This valuable contribution 

 to palaeontology, in which it is the purpose of the author "to deduce 

 from these remains, by physiological comparisons, the living habits 

 of the extinct species, to trace out their zoological affinities, and to 

 indicate their geological relations," is another gift in the last year for 

 ■which geologists are indebted to the British Association. Professor 

 Owen in his preface states, that the special researches which have 



