60 NATURAL HISTORY. 



and newts ; these in reality being much more nearly 

 allied to the fishes than to the genuine Reptiles. Linnaeus 

 also placed in this .unnatural class quite a number of 

 true fishes, such as the lampreys, sturgeons, skates, and 

 sharks. 



(4) Pisces, or Fishes. Except for the fact that Linnaeus, 

 as just remarked, had placed certain fishes among the 

 Reptiles, this class corresponds with what naturalists now 

 understand by the same name. The minor groups of 

 fishes were based upon the presence or absence of the 

 hinder or 'ventral' pair of fins, and the position of 

 these when present, a character of a quite artificial 

 nature; but several of his smaller divisions are very 

 natural. In the department of fishes, however, Linnaeus 

 had been preceded by Artedi, and such changes as were 

 made in the ' Systema Naturae ' upon the classification pro- 

 posed by the latter, were scarcely changes for the better. 



(5) Insecta, or Insects. Linnaeus was acquainted with 

 about three thousand species of Insects, but he included 

 under this head not only the true Insects, but also the 

 Spiders and Scorpions, the Centipedes, and many of the 

 Crustaceans (crab, lobster, &c.), none of these being, 

 properly speaking, Insects. In other words, the Insecta 

 of Linnaeus correspond with the 'Articulate Animals' of 

 later writers. Six orders of genuine Insects are recognised, 

 and are defined by the nature of their wings; and a 

 seventh order, under the name of Aptera, is retained for 

 the reception of the wingless insects and the other 

 Articulate Animals just mentioned. To a large extent 

 the classification of Insects which was adopted by 

 Linnaeus is the one which is now in use ; and there is 



