346 VERTEBRATE ANIMALS. 
becomes a question whether the group Bzmana should not have 
the value of a distinct sub-kingdom, whilst there can be little 
hesitation in giving Man at least a class to himself. 
ges’ 
188.—A, Skull of the Orang-outang; B, Skull of a European adult. 
In the words of Dr Pritchard, “ the sentiments, feelings, sym- 
pathies, internal consciousness, and mind, and the habitudes of 
mind and action thence resulting, are the real and essential 
characteristics of humanity.” 
TABULAR VIEW OF THE CHIEF DIVISIONS OF THE VERTEBRATA. 
SECTION A. ICHTHYOPSIDA :— 
Cass I, Pisces (FISHES).—Respiration by gills ; heart usually of 
one auricle and one ventricle ; blood cold; limbs, when present, in the 
form of fins. 
Order 1. Pharyngobranchiii—Ex. Lancelet. 
Order 2. Marsipobranchit.—£x. Lampreys and Hag-fishes. 
Order 3. Ze/eosted.—Ex. Eels, Herrings, Cod, Flat-fishes, Sal- 
mon, and Trout. 
Order 4. Ganoidet.—Ex. Bony Pike, Sturgeons. 
Order 5. ELlasmobranchiit.—Z£x. Sharks and Rays. 
Order 6. Dipnot.—Zx. Mud-fish. 
Cxiass II. AMPHIBIA.—Respiration at first exclusively by gills, after- 
wards by lungs, alone or associated with gills ; skull with two condyles ; 
limbs never converted into fins ; heart of the adult composed of two 
auricles and one ventricle, 
