'?. '.<' 



Il'llil'ip 







■rWi,;;, 



60 



Pisces — Continued. . - 



Ilaplomi 34 



IsospomhjU 70 



PlectospomhjU 150 



kSq/pliophori 



Nemningnathi 27 



yotavanihi 



Glanencheli 



Ichthyoccphali ■, 



Holostomi ... ■ 



Eiichehjccphali 2 



Coloccphali 3 



Hulecomorpld 2 



Ginglymodi 15 



y Glaniostomi 30 



Selachostomi 1 



IlolocephaU 2 



Plagiosiomi 46 



Dipnoi , 



81G 



Dermopieri 8 



Leptocardii 1 



Total species of Vertebrata 2, 240 



This number is considerably below tbe truth, as many of the fishes, 

 both of the ocean and of the fresh waters, remain undescribed. 



It is more difiScult to state the number of species of the inferior divis- 

 ions of the animal kingdom. It is asserted that 8,000 species of Cole- 

 opterous insects have been discovered in the IllTearctic region, and that 

 this is i)robably about two-thirds of the whole. This would give 12,000 

 species of this the most numerous order, and the Lepidoptera, ITymenop- 

 tera, and Diptera will follow at no great distance. Probably 50,000 is 

 below the mark as an estimate of the number of species of insects of this 

 region. One thousand species are to be added for the remaining Arthro- 

 poda — say, 200 Myriopoda^ 400 Araclinida, and 400 Crustacea. Of worms j 

 of land and water there are numerous species, the greater proportion 

 of which are not yet known to science. 



The number of the Mollusca and Molluscoida from the coasts and inte- 

 rior of the North American region is about 1,824, of which only 400 are] 

 marine. Of the remainder, 1,034 live in the numerous rivers and lakes, 



