GENERAL CLASSIFICATION. 475 
General Classification of Phylum Chordata 
{ 
aj Carinatze i 
ass J} Odontolcz (extinct). 
Birps, {ei (running). Class Mammats, 
Saururz (extinct). : ‘ ‘ 
3. Eutheria, Placentalia, Monodel- 
A Crocodilia (crocodiles, phia: the higher placental ° 
etc.). mammals. 
Ophidia (snakes). : Seed : 
Lacertilia (lizards, | 2, Metatheria, Marsupialia, Didel- 
Cl etc.). phia: Kangaroos, etc. ; young 
Rep oS Rhynchocephalia— born precociously, usually nur- 
| wp SEMtiLes. Sphenodon. tured in pouches. 
3 2 Chelonia (tortoises, 
2; etc.). s 
4 a Extinct Reptiles —|S-1. Prototheria, | Monotremata, Or- 
3 é . (maity orders). nithodelphia: oviparous, Ornz- 
an thorhynchus and Echidna. 
aziz ~- —- 
< 7 Sauropsida. Mammalia. 
z\oO . 
< in Amniota, embryos with amnion and allantois. 
OT§ 
= YE] Class ; 
5 {2 | Fisues.—e.g. Dipnoi(double-breath- Class 
= Oo ing nud-fishes). —|S-AMPHIBIANS.— 
A, Teleostomi (modern bony Anura (tailless frogs, etc.). 
By fishes and ‘‘ Ganoids”). Urodela (tailed newts, etc:). 
> Elasmobranchii (skate, Gymnophiona (worm-like Ca- 
a shark, etc.). cilia, etc.). 
Extinct Stegocephali (Lady: 
rinthodon, etc.). 
Ichthyopsida (fishes and amphibians). 
Class Hypostomata (extinct). 
Class Cyc.osromata (Round Mouths), without true jaws. 
Myxine, hag-fish. Petromyzon, lamprey. 
F Salpa type. 
Sus-Puytum | Ascidian type (sea- 
Urocuorpba or squirts).  « 
TUNICATA. Afppendicularia (lay- 
val type persistent). 
Sus-PHyLuM CEPHALOCHORDA.—A miphi- 
oxus or Lancelet. 
Surviving offshoots of ancestral Vertebrates. 
Puytum HemicHorpa or ENTEROpNEuSTA (offshoots of incipient Vertebrates ?). 
Balanoglossus, etc.; probably Cephalodiscus ; possibly Rhabdopleura, 
Ancestry of Vertebrates 
It is not at present possible to trace the path along which Vertebrates 
have evolved, though our faith in the doctrine of evolution—as a modal 
