PREFACE. 2^'x 



VERTEBRATA. 



BRANCH. UROCHORDA (TUNICATA). 



Class 1. Larvalia. 

 2. Saccata. 



BRANCH. CEPHALOCHORDA. 



Class. Leptocardia. 



BRANCH. CRANIATA. 



GRADE A. CYCLOSTOMA. 



Class. Cyclostoma. 



GJiABE B. GNATUOSTOMA. 



Grade a. Heterodactyla Iranchiata. 



Class 1. Pisces. 

 2. Dipnoi". 



Oracle /3, Pentadactyla Iranchiata. 

 Class. Amphibia. 



Grade y. Pentadactyla lipohranchia. 



Class 1. Eeptilia. ) ^b^.^^,j^_ Monocondyla. 



2. Aves. ) ^ 



3. Maimnalia. = Branch. Amphicondyla. 



APPENDICtJLATA. 



BRANCH. CH^TOPODA. 



Class 1. Oligochffita. 

 Class 2. Polychasta. 



BRANCH. ROTIFERA. 



Class. (Orders onlyi) 



BRANCH; GNATHOPODA (ARTHROPODA). 



GRADE A. MALACOPODA. 



Class. Peripatidea. 



GRADE B. CONDYLOPODA. 



Class 1. Crustaceai 



2. Hexapoda. 



3. Myriapoda. 



4. Arachnida.* 



* Followiug Prof. Ed. Van Beneden, I include Limulus, the Eurypteriha, and 

 Trilobites under the Arachnida as Branohiopulmonata. 



