96 



On the Classification of Animals 



The term hemitf/pic has been shown in the preceding paper to 

 imply in general a grade of the degradational. But, in some 

 groups, as in the class of Fishes among Vertebrates, it is appli- 

 cable to cases which are not typical because of their being inter- 

 mediate between the type of the group and a superior type or 

 types (p. 77). 



Typical groups, or more properly, the groups above the degra- 

 dationalj may be of several grades. Thus under Vertebrates, the 

 classes of Mammals, Birds, and Reptiles, represent different grades 

 of Vertebrate types, and the grades may be designated in order, 

 AlpliatypiG, Betatypic^ Gammatypic (from the first three Greek 

 letters, a, ^S, y). Under Mammals also, there are three grades, 

 those of Man, Megasthenes, and Microsthenes ; then, below these, 

 the hemitypic or degradational Ootocoids. Under tribes, families, 

 and genera, the number of grades may be large. 



Degradational subdivisions are strictly hypotypic, or below the 

 typical range. 



Typical subdivisions, or those above the degradational, are not, 

 in all cases, true typical, as well exemplified by the orders of 

 Fishes : the Teliosts alone being true typical, and the Ganoids and 

 Selachians, called hemitypic above, being properly hypertypic, or 

 above the typical range. Another example of this is afforded by 

 the subdivisions of Megasthenes. Carnivores and Herbivores ai^e 

 different grades of the true typical, the former the more perfect, 

 or eutypic; while the Quadrumanes or Monkeys are hypertypic, 

 being an intermediate type between the typical Megasthenes and 

 Man ; and the Mutilates (Cetaceans, &c.) are hypotypic. Among 

 the Microsthenes, the Chiropters or Bats are hypertypic, the Insec- 

 tivores and Rodents true typical of two grades, and the Edentates 

 hypotypic. 



Among the subdivisions of Mammals there are three grades of 

 true typical ; and of them man is archetypic, as he has been 

 styled, being the one perfect type. 



Degradational forms may be classed under three heads, as 

 follows : — 



1. Degenerative ; in which the forms are thoroughly animal in 

 type. The methods of decephalization which lead most commonly 

 to degenerative forms are the analytic, multiplicative, elliptic, and 

 defunctionative. 



2. Hemiphytoid ; when, without an internal radiate structure, 

 the species are {a) attached to a support, like plants (see defunc- 

 tionative method, p. 84); (6), budding (gemmative^ p. 91); (c), 

 radiate externally (^phytozoic, case a, p. 89). 



The externally radiate structure is a lower grade of hemiphy- - 

 toid degradation than either, being attached, or gemmate. 



3. Phytoid (from (j^wov, a plant) ; when the structural arrange- 



