President's Address. 147 



were included in the text. The others he reserved for a 

 projected series of supplementary monographs, of which only 

 one ever appeared, namely, that on the fishes of the Old Eed 

 Sandstone, which was completed in 1846. In this work sixty- 

 seven Scottish species are figured and described, and some 

 improvements in classification effected by the establishment 

 of the new families of Cephalaspidce, Acanthodidce, and Sauro- 

 dipterini, the two former being dismembered from the old 

 heterogeneous Zepidoidei, and the latter partly from the 

 Lepidoidei and partly from the so-called Sauroidei. 



But the undescribed carboniferous species enumerated in 

 his larger work remained undescribed, and to many of these 

 there is now no longer any clue. It is evident that in such 

 cases, should the identity of any of them with species subse- 

 quently described under different names by other authors be 

 satisfactorily proved, Agassiz's names can have no right to 

 priority, but must be simply cancelled. 



In offering a few words of comment upon the labours of 

 Agassiz in this department, the highest tribute of honour 

 must be paid to him for the position to which he raised the 

 science of fossil ichthyology, as well as for the enormous 

 amount of work which he accomplished in so short a time. 

 Eminent as well in other branches of zoology, his name will 

 go down to posterity as that of one of the greatest naturalists 

 of the present century. To him we owe the establishment of 

 the order of Ganoid fishes, the description of an enormous 

 array of genera and species, and the first valuable generalisa- 

 tions as to the history and succession of ichthyic life on the 

 globe. An opponent of the so-called vertebral theory of the 

 skuU, as held by Oken, and modified by Owen and others, as 

 well as of the doctrine of descent, he nevertheless pointed out 

 what, as Professor Marsh says, " is now thought to be one of 

 the strongest points in favour of evolution," namely, the cor- 

 respondence between the heterocercal character of the tail in 

 the embryo.B of modern osseous fishes, and the prevalence of 

 that form among the adult fishes of the older formations, 

 stating, in fact, that " les poissons fossiles du vieux gres rouge 

 representent reellement I'age embryonique du regne des 

 poissons." But it is hardly possible for the zoologist of the 



