SERIAL CONNECTION AMONG ANIMALS. 63 



compared with those of America. Among Fishes, the family 

 of Lcibyrinthici, which is confined to the Indian and Pacific 

 Oceans; and that of Goniodonts, which is limited to the 

 fresh waters of South America, as that of Cestracionts is 

 to the Pacific. The comparative anatomy of Insects is 

 not sufficiently far advanced to furnish striking examples 

 of this kind. Among Insects, however, remarkable for 

 their form, which are limited to particular regions, may 

 be quoted the genus Mormolyce of Java, Pneumora of 

 the Cape of Good Hope, Belostoma of North America, 

 Fulcjora of China, etc. The geographical distribution 

 of Crustacea has been treated in such a masterly manner 

 by Dana, in his great work upon the Crustacea of the 

 United States Exploring Expedition, vol. xiii, p. 1451, that 

 I need only refer to it for numerous examples of localized 

 types of this class, and also as a model how to deal with 

 such subjects. Among Worms, the genus Peripates of 

 Guiana deserves to be mentioned. Among Cephalopods, 

 Nautilus of Amboyna. Among Gasteropods, the genus lo 

 of the western waters of the United States. Among Ace- 

 phala, the genus Trigonia of New Holland, certain Naiades 

 of the United States, the genus Aetlieria of the Nile. 

 Among Echinoderms, Pentacrinus of the West Indies, Cul- 

 cita of Zanzibar, Amblypneustes of the Pacific, Temno- 

 pleurus of the Indian Ocean, Dendraster of the western 

 coast of North America. Among Acalephs, Berenice of 

 New Holland. Among Polypi, the true Fungidce of the 

 Indian and Pacific Oceans, the genus Renitta of the 

 Atlantic, etc. 



Many more examples might be quoted, were our know- 

 ledge of the geographical distribution of the lower animals 

 more precise. But these will suffice to show, that, whether 

 high or low, aquatic or terrestrial, there are types of ani- 



