XVI 



PREFACE. 



my experience as teacher and examiner has shown me that English students 

 are thoroughly familiarised. 



I. 



SUB-KINGDOMS. 



Protozoa. 



(Rhizopoda, Gregarinida, 



Radiolaria, Spongida.) 

 Infusoria, 

 ccelentkrata. 



(Hydrozoa, Aclinozoa.) 

 Axxuloida. 



(Scolecida, Echinoderma.) 

 Axnulosa. 



(Crustacea, Araclmida, 



Myriapoda, Insecta, Clue- 



tognatha, Annelida.) 



MoLIiUSCO'iDA. 



(Polyzoa, Brachiopoda, 



Tunicata.) 

 Mollusca. 



(Lamellibrauchiata, Bran- 



chiogastropoda, Pulmo- 



gastropoda, Pteropoda, 



Cephalopoda.) 

 Vertebrata. 



(Pisces, Amphibia, Rejitilia, 



Aves, Mammalia.) 



Seeing that one of my chief objects in superintending the translation of 

 the treatise to which these few pages are introductory, has been to he able 



* The Protozoa in Nos. II. and III. inclnde the same organisms as in No. I., 

 excepting that the Infusoria are included in that phylum in Nos. II. and III., and that 

 the Sponges are excluded, being in No. II. placed under the Ccelenterata, and in 

 No. III. forming the phylum Porifera under the " grade " Coelentera, as shown in the 

 genealogical tree on the adjacent page. 



f The Vermes of No. II. include all the Annulo'ida of No. I. excepting the 

 Ecliinoderma, which are raised to the rank of an independent phylum. They also 

 include the Annelida (Cha^topoda, llirudinea, and Gcphyrea) from amongst the 

 Annnlosa of No. I. and the Polyzoa from amongst the Mollusco'ida of the same series. 



J The Brachiopoda, raised to the position of a distinct phylum in No. II., are 

 placed among the Mollusco'ida in No. I. and amongst the Mollusca in No. III. 



§ The Tunicata, considered as an independent phylum in No. II., arc found 

 amongst the Mollusco'ida in No. I. and form a section of the Vertebrata in No. III. 



The Platyhelmia, Gephyrea, Enteropneusta, Nematoidea, and Chatognatha 

 form in No. III. a number of independent phyla. Together with the Polyzoa 

 (included in No. III. under the Mollusca), the Rotifera, and the Cluetopoda, included 

 under the Appcndiculata, they constitute the scries of phyla which are in No. 11. 

 massed together as " Vermes." 



Tf The Appendiculata include animals with lateral locomotive appendages, and 

 usually a segmented bod}'. The group is, excepting that it has the addition of the 

 Rotifera, nearly co-extensive with the Annulosa of No. I. 



** The phylum Mollusca in No. III. includes the Polyzoa and Brachiopoda, 

 excluded from it in both No. I. and No. II. 



ft The Vertebrate phylum in No. III. includes the Tunicata, which it will be seen 

 by reference to page 70 are already placed on the Vertebrate stem by Professor 

 Gegenbanr. 



