President's Address. 155 



journey to Scotland, and, having collected a large number 

 of specimens both in Caithness and in Orkney, packed them 

 in barrels, and shipped them off bodily to St Petersburg. 

 There they were placed at Pander's disposal for descrip- 

 tion, and the results are embodied in the three works last 

 quoted. In these works Pander does not concern himself 

 very much with species, but in one case, that of Pterichthys, 

 he maintained that Agassiz and Eichwald together had upon 

 its fragmentary remains constructed certainly not less than 

 fourteen genera, and that five others probably belonged to 

 the same category. British palaeontologists have, however, 

 not yet accepted his views as to the necessity for cancelling 

 the name Pterichthys, on the ground that the fragments pre- 

 viously named Asterolepis by Eichwald in reality belonged 

 to the Pterichthys of Agassiz, and that consequently the 

 name Homosteus of Asmuss must be substituted for Astcrolepis 

 of Agassiz and Hugh Miller. The question is certainly a 

 very difficult and delicate one, owing to the very fragmentary 

 nature of the remains from which Eichwald took his descrip- 

 tions and figures. The main feature in Pander's work was 

 his elucidation of structure, and his clear insight into the 

 fact that only by careful and laborious investigation into the 

 structural features of the skeleton, external and internal, can 

 we hope to determine the natural affinities of fossil fishes. 

 Here his achievements surpassed all that had been previously 

 done in palaeozoic ichthyology. The structure of the Placo- 

 dermata (Pterichthys, Coccosteus, Asterolepis, Heterosteus) is 

 minutely described and illustrated, as also of the Saurodip- 

 terini (Osteolepis, Diplopterus). A like treatment is accorded 

 to Dipterus, for which he institutes the family Ctenodipteriiii, 

 in which he also provisionally includes Geratodus, then only 

 known as a mesozoic fossil, and to Cheirolepis, which he also 

 erects into a distinct family, fully corroborating the views of 

 Hugh Miller and of Giebel as to its place not being among 

 the Acanthodei, as Agassiz had imagined, as well as indicat- 

 ing that he was not unaware of its resemblance to Palceoniscios. 

 The singularly beautiful and complicated microscopic struc- 

 ture of the Old Eed Sandstone teeth, so well known as 

 Dendrodus, Lamnodus, etc., is minutely described and mag- 



