GENERAL CLASSIFICATION 141 



TABLE OF WORMS. 



Order 1. — Cylindricai Worms. 



[Nematodes, cestodes, and other flat and round worms. H. E.] 



Gordius [Nematode. H. E.]. Cuoullanus. 



Filaria (guinea-worm). Strongylus. 



Probosoidea [Turbellarian. H. E.]. Soolex [head of tapeworm. H. E.]. 



Crino. CaryophyUaeus [Cestode. H. E.]. 



Asoaris [Nematode. H. E.]. Tentaoularia. 



Eissula. Echinorhyncus 

 Trichocephalns [Nematode. H. E.]. [Aoanthooephala. H. E.]. 



Order 2. — Bladder Worms. 

 " Bicome." 

 Hydatis. 



Order 3. — Flat Worms. 

 Taenia [Cestode. H. E.]. Lingula [doubtless a misprint for 



Ligula, a Cestode. H. E.]. 

 linguatula [Arthropod. H. E.]. Fasciola [v. Introd. H. E.]. 



THIRD 8TA0E OF ORGANISATION. 



Nerves terminating in a ganglionic longitudinal cord ; respiration 

 by air-carrying tracheae ; circulation absent or imperfect. 



{Insects and Arachnids.) 

 INSECTS. 

 (Class V. of the Animal Kingdom.) 



Oviparous animals which undergo metamorphoses, which may have 

 wings, and which have in the perfect state six jointed legs, two antennae, 

 two eyes with facets and a horny skin. 



Respiration by air-carrying tracheae which spread everywhere ; no 

 circulatory system ; two distinct sexes ; a single copulation in the 

 course of their life. 



Observations. 



On reaching the insects we find among the extremely numerous 

 animals comprised in this class a state of affairs very different from 

 what we have met with in the animals of the four preceding classes ; 

 so instead of a gradual progress in the complexity of animal organisa- 

 tion we find on reaching the insects that a considerable leap has been 

 made. 



