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PROFESSOR LANKESTER. 



Classes and Orders of the YERTEBRATA. 



Class. 



I. Larvalia 

 II. Saccata 



Branch a. UROCHORDA. 



Order. 



r 



I 1. Ascidise . 



I 



I 2. Luciae . 

 1 3. Thaliacea 



E.vamples. 



(Appendicularia, 

 Kowalewskyia. 

 fAscidia. 

 -{ Clavellina. 

 X^Botryllus. 

 Tyrosoma. 

 f Salpa. 

 \BoUolum. 



Branch b. 

 I. Leptocardia . 



CEPHALOCHORDA. 



Amphioccus. 



Branch c. CRANIATA. 



Grade A. Cyclostoma (Monorrliina). 



■r TT f Myxine. 



I. Hyperotreta. . . . |^£^^,,^,^^. 



11. Hyperoartia . . . Petromyzon. 



Grade B. Gnathostoma (amphirrina). 

 Subgrade a. Heterodactyla branchiata» 

 jj' -p. > (See separate Lists). 



Subgrade b. Pentadaciyla hranchiata. 

 I. Amphibia (See separate List). 



Subgrade c. Pentadaciyla lipobranchia. 

 Branch A. Monocondyla. 



yy' . >- (See separate Lists.) 



Branch B. Amphicondyla. 

 I. Mammalia (See separate List) . 



