In the fractal divisions of Theosphy each stage and cycle and plane is divided into seven subdivisions of the same.  This goes for the evolutionary cycles of man as much for everything else.  If then we take the Earth globe (era) of the present evolutionary or cosmic Round, this is made up of seven great Racio-Spiritual divisions, called "Root Races", which represent the recapitulation of the Rounds as a whole.  These are as follows

1) Polarians 
2) Hyperboreans 
3) Lemurians 
4) Atlanteans 
5) Aryans 
6) 6th Root Race 
7) 7th Root Race

The first root race was primarily spiritual (Astral/Etheric), and did not leave physical remains.  The second (tee Hyperborean) were also non-physical (etheric).

The Lemurians were the first with physical bodies.  They were described as a race of three eyed giants and inhabited a "lost continent" of Lemuria which is where the Indian and Pacific oceans now are.  Mdern theosophists identify Lemuria with the actual ancient supercontinent of Gondwana.

The Atlanteans are generally considered to have had great occult and/or technological powers, and inhabited the lost continent of Atlantis, which was destroyed due to their abuse of psychic powers or whatever (the versions of this late 19th/early 20th century myth of hubris and the arrogant Atlanteans, given by Blavatsky, Leadbeater, Steiner, A. Bailey, Edgar Cayce, and others all differ in detail).  The survivors became the present fifth or Aryan race.

The Atlantean Root Race consisted of the following sub-races

1) Rohmahls 
2) Tlavatlis 
3) Toltecs 
4) First Turanians 
5) Original Semites 
6) Akkadians 
7) Mongolians

It was from the 5th sub-race of Atlanteans, known today as the Semites, that the first Aryans emerged (not the rigid symbolism, the 5th subrace becomes the 5th race), migrating to India and producing what was known in those distant times as the Rama Empire. According to one interpretation they were rivals to the Atlanteans in the leadership of the ante-dilluvian World and it led to a war between the two empires, including ancient nuclear warfare.

The Fifth Root Race - the Aryan 
According to Theosophical doctrine we are presently at the fifth stage, referred to as the Aryans.  A few words about this term.  Ethnologically, the Ayrans (the word means "noble" in Sanskrit) were the original Indo-European nomadic tribesmen, a war-like race of horsemen that moved east to India and West into the near East and Europe.  Feminist historians argue that when they got to Europe they destroyed the peace-loving earth-wisdom pagan matriarchal societies and replaced them with war-like sky-god worshipping patriarchal societies such as we still have today.  It is unfortunate that the term "aryan" was adopted and perverted by Hitler and his intellectual predecessor's fantasies of an "Aryan" Overman, and is still used today by right-wing white power extremists.  It has actually been suggested (by Trevor Ravenscroft in his classic work "Spear of Destiny) and by others as well, that Hitler and his inner circle were actually black magicians and perverted the genuine symbols, e.g. turning the swastika (a solar symbol) counter-clockwise (we are asuming here the trailing edges are "blown back" and pointing the opposite direction to the rotation), in order to focus on destruction and negativity (note the swastika on the Theosophical logo spins "clockwise").  Other critical historians and history of occult scholars tend to pooh-pooh or downplay the idea of Hitler having occult knowledge.  He did consult astrologers, but that doesn't make him an occultist.  Also swastikas in India, Tibet, and elsewhere are represented counter-clockwise as well as clockwise anyway.  Taking the middle way perhaps the best explanation my own opinion here lies midway between the believers and the critics.  In any case it should be understood that Aryan when used in the Theosophical context has absolutely nothing to do with Hitler or Nazism, and the sort of racist ideology espoused by white power etc would be abhorrent to every Theosophist.

This is not to say that the early orthodox and heterodox theosophists like Blavatsky, Leadbeater, and Steiner were totally free of racism.  In fact their writing are just full of the entrenched white colonial european ethnocentrism that dominated the nineteenth and early twentieth centuries.  The current Root Race, the apex of human evolution, is still European.  At least one passage in Blavatsy's writings point at anti-semitism (the Jews are referred to as an unnatural bridge between the 4th and 5th races).  Tribal peoples are referred to by Leadbeater and Steiner as "the savage", the lowest rung on the human evolutionary ladder, and Leadbeater goes into some detail comparing the aura of the "savage" with that of the civilised (European) man.  According to Gregory Tillet in his excellent biography (Elder Brother), Leadbeater was also a mild racist who hated being in India where the Theosophical headquarters were (the Adyar Branch in Madras).  Interestingly, Steiner rejected the term Aryan for the fifth Root Race, preferring the clumsy "Post-Atlantic".  Nevertheless his writings reflect eurocentric prejudice every but as much as his predecessors.

The constituent "sub-races" of  the Aryan (5th or present) race are as follows

1) Hindus 
2) Sumerians 
3) Egyptians 
4) Hellenes 
5) Europeans 
6) Nova men 
7) ?

These exact same stages were used by Rudolph Steiner as the seven culture periods of the Post-Atlantic (current) era.

The 6th race constitute a new coming racial expression, which will demonstrate a group consciousness and telepathic rapport, high intelligence and intuitive skills, combined with numerous other qualities.  This formulation, very innovative and forward looking when it first appeared, now seems very dated, as the future of nanotech, cyborgs, genetic engineering, transhumanism and the Singularity seems like drastically overtaking any theosophical version of a coming race.

The concept of Root Races was also adopted, along with so much else of Blavatsky's teachings, by Rudolph Steiner and the Anthroposophical movement he founded.

The Theosophical and Anthroposophical Timescales compared with geology and science

 The Meme/Theme of Root Races

Theosophy and Root Race Links

Evolution in the Fourth Round - David Pratt. Very good coverage.

Destiny of the Human Race - by Omega

The Antiquity of Man and the Geological Ages By Charles J. Ryan