APPENDIX 



547 



posed, based upon a more complete study of anatomical 

 characters. Through these the extinct genus Anaptomor- 

 phus, which is probably very near the direct ancestral 

 line leading to Man, has been placed in Sub-order 3, 

 Anthropoidea, and with it has been placed the living genus, 

 Tarsius, a closely related form. 



For convenience in classification all the descendants of 

 the Condylarthra, together with this latter, but excepting 

 the aberrant Sirenia, are often grouped together under 

 the single Order of Ungulata, or hoofed animals, connected 

 both by descent and by the common peculiarities embodied 

 in the name. This will include Orders 11-21 in the above 

 list. In the same way the Creodonta may be included in 

 the Carnivora, although the Cetacea are treated as a sepa- 

 rate, though allied group. The Galeopithecoidea are often 

 included within the Insectivora. This reduces the Orders 

 of placenta! mammals to nine, viz : Insectivora, Cheiroptera, 

 Edentata, Rodentia, Primates, Ungulata, Sirenia, Cetacea, 

 Carnivora. There are, of course, as in all groups of ani- 

 mals, many other possible arrangements, the differences 

 being based on the relative value of the various groups, 

 their relationships to one another, and the comparative de- 

 gree of specialization of each ; points upon which there is 

 much room for difference of opinion.] 



Owing to the extinction of so many of the groups, especially 

 those forming the connection between two others, a classification 

 that rests wholly upon living forms is far from complete and in 

 some points differently arranged from one that includes all 

 known forms. Thus among the fishes the selachians alone are 

 left of all the elasmobranchs ; a few remnants remain of the first 

 few Orders of teleostomes, isolated from one another and from 

 the others ; and of the Holocephali and Dipnoi only a few species 

 occur. Among the amphibians, the Stegocephali, the most im- 

 portant Order of all, have disappeared entirely, and among the 

 reptiles a still greater destruction has left but four isolated spots 

 in a once continuous history. This loss has affected also all the 

 transition forms between reptiles and the modern type of birds, 

 and completely isolated the Aves from all related forms. The 

 mammals are still rich in Orders but the synthetic types that once 

 united them have long since disappeared. Without going into 

 the Sub-Orders this abbreviated classification, in some respects 

 different from the above synopsis, may be given here for con- 

 venience in comparison. Only the gnathostomes may be con- 

 sidered. 



