On this page there is a circular decoration around the Arabic ayah (verse) number:
What are these decorations called?
According to this page, it seems that the circles have no specific name, but they are used to indicate the ayah number:
Ayah (pl. Ayat), Verses. Ayah is a word which signifies "sign." It was used by Muhammad for short sections or verses of his revelation. The division of verses differs in different editions of the Arabic Qur'an. The number of verses in the Arabic Qur'an are recorded after the title of the Surah, and the verses distinguished in the text by a small cypher or circle. The early readers of the Qur'an did not agree as to the original position of these circles, and so it happens that there are five different systems of numbering the verses:
(a) Kufah verses. The Readers in the city of al-Kufah say that they followed the custom of 'Ali. Their way of reckoning is generally adopted in India. They reckon 6,239 verses.
(b) Basrah verses. The Readers of al-Basrah follow 'Asim ibn Hajjaj, a Companion. They reckon 6,204.
(c) Shami verses, The Readers in Syria (Shiim) followed 'Abdu 'lliih ibn 'Umar, a Companion. They reckon 6,225 verses.
(d) Makkah verses. According to this arrangement, there are 6,219 verses.
(e) Madinah verses. This way of reading contains 6,211 verses.