Trinomial nomenclature of classification was proposed by Huxley and Strickland.

Trinomial nomenclature is a system of naming organisms in which three names are used to denote the genus, species, and subspecies. This system was proposed by Thomas Henry Huxley and Hugh Edwin Strickland in the mid-19th century. It is a modification of the binomial nomenclature system proposed by Carl Linnaeus.

1. Binomial nomenclature
- Carl Linnaeus, a Swedish botanist, proposed the binomial nomenclature system in the 18th century.
- Binomial nomenclature uses two names, the genus name and the species name, to identify and classify organisms.
- The genus name is written first and always starts with a capital letter, while the species name is written second and starts with a lowercase letter.
- Both names are always italicized or underlined when handwritten.

2. Need for trinomial nomenclature
- While binomial nomenclature was a significant improvement over the previous systems of naming organisms, it did not provide a way to differentiate between different subspecies or varieties within a species.
- There was a need to develop a system that could accommodate the naming of subspecies or varieties to provide a more precise classification.

3. Introduction of trinomial nomenclature
- In response to the need for more precise classification, Huxley and Strickland introduced the trinomial nomenclature system.
- This system added a third name, the subspecies name, to the genus and species names.
- The subspecies name is written third and is often written after a trinomial sign (e.g., "ssp." or "subsp.").
- The subspecies name can help distinguish between different populations or varieties within a species.

4. Example of trinomial nomenclature
- An example of trinomial nomenclature is the scientific name of the African lion, Panthera leo leo.
- In this example, "Panthera" is the genus name, "leo" is the species name, and "leo" is the subspecies name.
- The trinomial name "Panthera leo leo" specifically refers to the subspecies of the lion found in Africa.

Conclusion:
In conclusion, the trinomial nomenclature system was proposed by Huxley and Strickland as a modification of the binomial nomenclature system. It allows for the inclusion of a subspecies name, providing a more precise classification for organisms.