KEPORT ON ZOOLOCy. 159 



Before arriving at the classes of the Vertehrata, Latreille adopts 

 a previous division of this series into Ha:matherm.a (with wai-m 

 blood,) and Hcemacrytna (with cold blood) . This last is again 

 divided into Pulmonea and Solibranchia, according as the re- 

 spiration is carried on by lungs or gills. In like manner we 

 find his second series, Cephalidia, divided into the three races 

 of Mollusca, Elrninthoida (comprising the classes Cirripedes 

 and Annelkles), and Condylopa (with articulated feet). The 

 Acephala also into Gastrica and Agastrica. Few will probably 

 prefer Latreiile's three primary divisions to Cuvier's four types, 

 or judge his arrangement on the whole to be more natural than 

 that of the Regne Animal. His Cejihalidia, in particular, bring 

 together under one head two very distinct groups which are well 

 separated by Cuvier. 



The above are some of the principal systems, or modifications 

 of that of Cuvier, which have been brought forwards since the 

 first edition of the Rigne Animal * , In 1829 appeared the 

 second edition of the work just mentioned, in which however 

 there is no material alteration, at least as far as regards the dis- 

 tribution of the leading groups- 



It may be thought by some that the subject is hardly deserving 

 so much notice ; that the consideration of different systems, 

 some of which perhaps we feel sure are grounded upon errone- 

 ous principles, may be passed over as of not much importance 

 to zoology. Cuvier will teach us to judge otherwise. He ob- 

 servest that the affinities of animals are so complicated, that 

 we ought thankfully to receive every endeavour to set them be- 

 fore us in a new point of view. There are few systems which do 

 not contribute something to our knowledge on this subject, and 

 which do not thereby enable us to make some further advance 

 towards that which is the end and object of the science, the 

 natural system itself J. 



III. Of the several Classes in the Animal Kingdom. 

 In entering on the consideration of the several classes of ani- 



• I have been obliged to omit the notice of certain worlds which may per- 

 haps contain some new views respecting the arrangement of animals, but which 

 I have been unable to get sight of. Such are the Elements of Zoology, (in Ita- 

 lian,) by Ranzani, published at Bologna in 1S19, &c. ; and the Manual of Zo- 

 °l"9!/, (ill German,) by Goldfuss, published at Nuremberg in 1820. In 1828, 

 V'an der Hoeven also published a Tabular View of the Animal Kingdom, equally 

 unknown to me except by title. 



•f Hist. duProgres desSci. Nat., tom. iv. p. 182. 



t Mr. MacLeay has well observed that " every discovery of an affinity is, in 

 part, a discovery of natural arrangement." {Hor. Ent., p. 324.) 



