SB 12.7.22

evaṁ lakṣaṇa-lakṣyāṇi
 purāṇāni purā-vidaḥ
munayo ’ṣṭādaśa prāhuḥ
 kṣullakāni mahānti ca
Word for word: 
evam — in this way; lakṣaṇa-lakṣyāṇi — symptomized by their characteristics; purāṇāni — the Purāṇas; purā-vidaḥ — those who are expert in such ancient histories; munayaḥ — the sages; aṣṭādaśa — eighteen; prāhuḥ — say; kṣullakāni — minor; mahānti — great; ca — also.
Translation: 
Sages expert in ancient histories have declared that the Purāṇas, according to their various characteristics, can be divided into eighteen major Purāṇas and eighteen secondary Purāṇas.