Portrait Series - $2

The $2 note shows a group of pupils interacting with a teacher in a "Borderless Classroom". Three prominent institutions of learning are seen in the background. From the extreme right, the institutions are Victoria Bridge School, the old Raffles Institution at Bras Basah Road, and the College of Medicine. Besides being closely associated with the late Encik Yusof at various stages of his life, the three institutions also symbolically represent the ideal educational progression in Singapore, namely primary, secondary and tertiary.

Also on the front of the $2 note is the Money Cowrie (Cypraea moneta Linnaeus, 1758). As its name implies, it was commonly used as a form of currency among the communities in the Indian and Pacific Oceans during the past. Humans have carried shells of this particular species to practically all parts of the world because of their beauty and remarkable gemlike shape and handy size.

The back of the shell is usually yellow, with a fine filamentous red ring. This species is found in the shallow inter-tidal zone of rocky shores and has a wide distribution in the Indo-West Pacific region.

Portrait Series - $5

The Garden City Theme exemplifies Singapore as a garden city, the pride of our citizens. The back of the $5 note features a dramatic Garden City landscape dominated by the portrayal of the old tembusu tree (Fagraea fragrans) which still stands in the grounds of the Singapore Botanic Gardens. The majestic tree of more than 200 years is characterised by its firm and towering presence. The tree bears small red berries and has white flowers that are exceptionally fragrant. The sturdy tree with its highly branched canopy, epitomises the spirit of Singapore - strong, resilient and continuously striving for progress.

Also pictured on the front of the $5 note is the Gold-Ringed Cowrie (Cypraea annulus Linnaeus, 1758). Like its relative the Money Cowrie, this species is very abundant and is found living in the inter-tidal zone, usually in shallow tide pools high above water level. It is also one of the more variable species in the genus.

A typical Gold-Ringed Cowrie has a greenish-yellow back, encircled by a bright orange-yellowish band with a cream-coloured base. The egg cluster, about the size of the animal, is light cream. Its distribution is in the Indo-West Pacific.

Portrait Series - $10

The Sports Theme is reflected in the $10 note through the depiction of five popular sports pursuits. On the back of the note, we see a jogger, a tennis player and a soccer player on one side, representing the most favoured land sports in Singapore. On the other side, swimming and sailing are pictured representing water sports. These are illustrated against a vibrant general design to convey the sense of energy and ruggedness symbolising sporting activities in general.

The note also shows the Wandering Cowrie (Cypraea errones Linnaeus, 1758). A variable member of the genus, this species is difficult to describe but easy to recognise by the mottled green top with a large, brownish and centrally located blotch. This blotch may vary in shape and size from specimen to specimen.

The size range is between 13 and 43 mm. Having an Indo-West Pacific distribution, this animal is a shallow-water resident, found at the inter-tidal zone and down to a few metres below mean low tide level. Although its numbers have declined in Singapore, it still remains the most common cowrie here.

Portrait Series - $50

The Arts Theme as the secondary design for the $50 note reflects the coming-of-age of the Singapore Arts scene. The design appropriately depicts a mix of four ethnic musical instruments. The Chinese Pipa, Malay Kompang, Indian Veena and Classical Violin epitomise Singapore as a confluence of Chinese, Malay, Indian and Western cultures. The instruments are complemented by portions of two local artworks in the Singapore Art Museum, entitled "Gibbon" and "Drying Salted Fish". The works represent the development and achievements of artists in the country.

The Cylindrical Cowrie (Cypraea cylindrica) decorates the front of the $50 note. The shell of this animal is cylindrically elongated and its back is bluish grey with a large central irregular blotch. It is found widely in central Indo-West Pacific and Micronesia, ranging from Okinawa, Japan, to northwestern Australia and from the Malay Peninsula to New Caledonia.

This species is moderately common in the inter-tidal and shallow sublittoral zones.

Portrait Series - $100

The Youth Theme exemplifies the aspirations, ruggedness and community spirit of youths in Singapore. On the back of the $100 note, these are represented by three aspects of youth activities, namely Youth in Community Service, Youth in Action and Youth in Leadership Development. On the left of the design is a group of uniformed youths representing the Singapore Red Cross, St John's Ambulance Brigade and the National Police Cadet Corps.
A National Service officer bearing a ceremonial sword stands against a backdrop of the magnificent tower of the SAFTI military institute.Situated in the centre of the design is a group of scouts engaged in an outdoor scouting activity.

The $100 note also carries the picture of the Swallow Cowrie (Cypraea hirundo Linnaeus, 1758). The mollusc is found over much of the Indo-West Pacific region and usually lives on wave-beaten reefs at low tide, under coral slabs and rocks. This species was originally described from Mauritius and India with other variations reported from as far as northwestern Australia and Japan.

The shell of this animal has two distinct dark brown spots on the ends and the surface is bluish green with minute brown speckles. It is moderately common in shallow rocky habitats.

Portrait Series - $1,000

The back of the $1,000 note features buildings representing the Executive, the Legislature and the Judiciary. The Istana building, the official residence of the President of Singapore, symbolises the President and the Executive. It is depicted in the centre of the design. Flanking the Istana are the Parliament House on the left and the Supreme Court building on the right. The Parliament House and the Supreme Court represent the Legislature and the Judiciary respectively.

The $1,000 note also features the Beautiful Cowrie (Cypraea pulchella Swainson, 1823). This animal was considered another of the rare gems of the genus until about 1968. The graceful pear shape, contrasting large chestnut blotches and distinctly marked teeth make this cowrie unusually attractive. Specimens of this species are quite common and are usually found offshore from depths of 30 m to 140 m.

They are found over a wide range although most old collections were reported from the Chinese coast of Hong Kong.

Portrait Series - $10,000

The back of the $10,000 note depicts the future direction of our economy, one which is knowledge-based and technology-driven. It features a research scientist working on high-technology laboratory equipment. A microprocessor and a silicon wafer, representing Singapore's drive to create a high-tech manufacturing hub, are seen in the backdrop on the left and right-hand side respectively. Partial sequences of two proteins, the tyrosine kinase and the tyrosine phosphatase, representing two important breakthroughs in research by the Institute of Molecular and Cell

Biology (IMCB) appear at the top. A subtle background pattern of the printed circuit board completes the design.

The Onyx Cowrie (Cypraea onyx Linnaeus, 1758) is also shown on the $10,000 note. The jet black base, the brown and usually banded back and the white pearly overlay on the sides or the whole shell make identification of this species easy. The mantle of the live specimen is greyish with many tiny circular dots very closely distributed on it. A variant of this animal from Sri Lanka is reportedly considered a food item.

An Indo-West Pacific cowries, this species has been reported from shallow muddy water in Singapore as well as at depths of 30 m or more in Japan.