PEEFACE. Xlx 



VERTEBRATA. 



BRANCH. UROCHORDA (TUNICATAt. 



Class 1. Larvalia. 

 2. Saccata. 



BRANCH. CEPHALOCHORDA. 



Class. Leptocardia. 



BRANCH. CRANIATA. 



GRADE A. CYCLOSTOMA. 



Class. Cjclostoma. 



GRADE B. GNATUOSTOMA. 



Grade a. Hcterodactyla branchiata. 



Class 1. Pisces. 

 2. Dipnoi. 



Grade fi, Pentadaetyla branchiata. 

 Class. Amphibia. 



Grade y. Pentadaetyla Ivpobranchia. 



Class 1. Keptilia. j = Branch . jfonocondyla. 



2. Aves. ) 



3. Mammalia. = Branch. Amphieondyla. 



Al'PENDICULATA. 



BRANCH. CILETOPODA. 



Class 1. 01igocha;ta. 

 Class 2. Polychasta. 



BRANCH. ROTIEERA. 



Class. (Orders only.) 



BRANCH. GNATHOPODA (ARTHROPODA). 



GRADE A. MALACOPODA. 



Class. Peripatidea. 



GRADE D. CONDYLOPODA. 



Class 1. Crustacea. 



2. Jlexapoda. 



3. Myriapoda. 



4. Arachnida.* 



* Following Prof. Ed. Van Beneden, I include Limulus, the Euryptorina, and 

 Trilobites ufader the Arachnida as Branchiopulmonata. 



