340 THE HISTORY AND SCOPE OF ZOOLOGY IX 



Branch III. Malacozoaria or Mollusca. 



Sub-Branch 1. Mollusca proper. 



Class I. CEPHALOPODA. Class III. GASTEROPODA. 



II. PTEROPODA. IV. ACEPHALA. 



Sub-Branch 2. Molluscoidea. 



Class I. TUNICATA. Class II. BRYOZOA. 



Branch IV. Zoophytes. 



Sub-Branch I. Radiaria. 



ClaSS I. ECHINODERMS. ClaSS III. CORALLARIA Or 



II. ACALEPHS. POLYPI. 



Sub-Branch 2. Sarcodaria. 



Class I. INFUSORIA. Class II. SPONGIARIA. 



In England T. H. Huxley adopted in his lectures 

 (1869) a classification which was in many respects 

 similar to both of the foregoing, but embodied im- 

 provements of his own. It is as follows : 



Sub-Kingdom I. Protozoa. 



Classes : RHIZOPODA, GREGARINIDA, RADIOLARIA, SPONGIDA. 

 Sub-Kingdom II. Infusoria. 

 Sub-Kingdom III. Coelenterata. 



Classes : HYDROZOA, ACTINOZOA. 

 Sub-Kingdom IV. Annuloida. 



Classes : SCOLECIDA, ECHINODERMATA. 

 Sub-Kingdom V. Annulosa. 



Classes : CRUSTACEA, ARACHNIDA, MYRIAPODA, INSECTA, CH^E- 



TOGNATHA, ANNELIDA. 



Sub-Kingdom VI. Molluscoida. 



Classes : POLYZOA, BRACHIOPODA, TUNICATA. 

 Sub-Kingdom VII. Mollusca. 



Classes : LAMELLIBRANCHIATA, BRANCHIOGASTROPODA, PULMO- 



GASTROPODA, PTEROPODA, CEPHALOPODA. 



Sub-Kingdom VIII. Vertebrata. 



Classes : PISCES, AMPHIBIA, REPTILIA, AVES, MAMMALIA. 



We now arrive at the period when the doctrine of 

 organic evolution was established by Darwin, and 

 when naturalists, being convinced by him as they 

 had not been by the transmutationists of fifty years' 

 earlier date, were compelled to take an entirely new 



