NUMBER AND RANK OF GROUPS. 273° 
of insects (Annulosa), pointing out the probable station 
of the Scarabeus Sacer of Mac Leay. 
Harputa VEXILLUM, Zool. Iil.2. pl. 77. ScCARABZEUS SaceR MacL. 
1. Kingdom. Animalia. 1. Kingdom. Animalia. 
2. Sub-kingdom. Mollusca L. 2. Sub-kingdom. Annulosa, 
(Mollusea, Radiata, Acrita, 
Mac.) 
3. Class. 'Testacea. (Mollusca 3. Class. Ptilota Arist. 
Mac.) 
4. Order. Gasteropoda Cuv. 4. Order. Coleoptera Lin. 
5. Tribe. Zoophaga. 5. Tribe. Chilognathiform 
(MacL.) 
6. Family. Volutide. 6. Family. Scarabezide Sw. 
(Petalocera Saprophaga 
MacL.) 
7. Sub-family. Volutine. 7. Sub-family.  Scarabe'nze 
Sw. (Scarabeide MacL.) 
8. Genus. Harpula Sw. 8. Genus. Scarabeus 
MacL. 
9. Sub-genus. Harpula proper. 9. Sub-genus. Helio. 
cantharus duct. 
(Scarabeus proper.) 
The demonstration of all these groups cannot, of course, 
now be entered upon, although full details will be given 
in their proper place. These, however, are the results ; 
and illustrate, in the most intelligible manner, the deter- 
minate number of graduated ranks of circles in the 
animal kingdom. 
(334.) Although we have not yet detected in the 
scheme of nature more than nine gradations of circles, it 
by no means follows that all these are constantly to be 
met with in every circle of superior magnitude; as, for 
instance, in classes or orders. This inequality in the 
contents of two groups of the same analogical rank has 
already been fully accounted for.* Sometimes, as in 
the order Raptores, the primary groups do not appear 
of a higher rank than the families of the Znsessores ; and. 
even of these, one, if not two, entire families are extinct. 
Aberrant groups are almost always fewer, both in point 
of numbers and of divisions, than such as are typical ; 
and sometimes an aberrant genus, instead of having 
many species, so as to contain its own types of form, 
will be only represented by a single individual. This, 
* See Preliminary Discourse on Nat. Hist. p..231. 
dh 
