118 Dr. C. F. Liitken on the Changes of Form in Fishes 



which constitute it are all armed with five very considerable 

 groups of card-like teeth on the vomer, the palatines, and 

 the pterygoids. These four species are : — the true P. rhomheus 

 of Forskal from the Red Sea and the Mauritius (figured in the 

 illustrated edition of Cuvier's ' E^'gne Animal,' pi. xlii. fig. 2), 

 which authors, except the late Sir John Richardson, have 

 erroneously confounded with P. argenteus^ Linn,, from the 

 East Indies, Australia, and China (see ' Voyage of the Ere- 

 bus and Terror,' pi. xxxv. fig. 1) ; P. falcifbrmis, Lac, 

 from the East Indies, and P. sebce, C. & V., from the west coast 

 of Africa. 



. The species of the genus Platax are subject during their 

 growth and development to such considerable changes, both 

 in physiognomy and in the form of the body and the colora- 

 tion, that great confusion and the establishment of a number 

 of nominal species could not but result from them. Never- 

 theless more light has by degrees been thrown upon this 

 question ; and in this respect I may refer especially to M. 

 Bleeker's text and the very instructive plates of his great 

 ' Atlas Ichthyologique.' But (and this is a singular fact) he 

 has neglected a character of which M. Klunzinger first indi- 

 cated the importance, and without which we shall never 

 arrive at a certain determination of the species. In some 

 species (P. teira, Forsk.) the three points of the teeth of the 

 outer row are of the same sizej in others (P. vespertilio, Bl., 

 = orbicularis) the middle point is very distinctly larger ; in 

 others, again (P. hatavia7ius and P. finnatus (L.), Blk.), it is 

 much larger than the others and completely predominant. It 

 would not appear that we know more than these four species ; 

 M. Bleeker's fifth species (P. melanosoma) is only known 

 from a very young specimen ; and the author (whose recent 

 loss is so much deplored) himself regarded it as doubtful. 



15, SCOMBEKESOX SAUEUS. 



Dr. Giinther having already indicated, although very briefly, 

 the metamorphoses of this fish in their principal features, I 

 may here confine myself to referring to the figures on p. 567 

 (of the Danish memoir), which represent the diiferent phases 

 of the evolution of the rostrum, as also the physiognomy of 

 the entire fish in one of its youngest stages ; and as they are 

 accompanied by a corresponding series of figures representing 

 the very well-known evolution of the same parts in the com- 

 mon Garfish [Belone vulgaris)^ the analogies and differences 

 between the development and transformation of these two 

 nearly allied fishes will strike the eye at once without need of 

 fui'ther explanation. I will only add that Scomber esox saur us . 



