The northern Cephissus river (Greek Κηφισσός: Kifissós, Kephissós, or Kêphissos) or Cephisus (Greek Κηφισός: Kêphisos) rises at Lilaea in Phocis

Phocis

Phocis is one of the regional units of Greece. It is part of the administrative region of Central Greece. It stretches from the western mountainsides of Parnassus on the east to the mountain range of Vardousia on the west, upon the Gulf of Corinth...

 and flows by Delphi

Delphi

Delphi is both an archaeological site and a modern town in Greece on the south-western spur of Mount Parnassus in the valley of Phocis.In Greek mythology, Delphi was the site of the Delphic oracle, the most important oracle in the classical Greek world, and a major site for the worship of the god...

 through Boeotia

Boeotia

Boeotia, also spelled Beotia and Bœotia , is one of the regional units of Greece. It is part of the region of Central Greece. It was also a region of ancient Greece. Its capital is Livadeia, the second largest city being Thebes.-Geography:...

 and eventually issues into Lake Copais

Lake Copais

Lake Copais, Kopais, or Kopaida used to be in the centre of Boeotia, Greece, west of Thebes until the late 19th century. The area where it was located, though now a plain, is still known as Kopaida.- Drainage :...

 which is therefore also called the Cephisian Lake. This Cephissus is the modern Mauro Potamo.

Pausanias

Pausanias (geographer)

Pausanias was a Greek traveler and geographer of the 2nd century AD, who lived in the times of Hadrian, Antoninus Pius and Marcus Aurelius. He is famous for his Description of Greece , a lengthy work that describes ancient Greece from firsthand observations, and is a crucial link between classical...

 (9.38.7) records a Theban

Thebes, Greece

Thebes is a city in Greece, situated to the north of the Cithaeron range, which divides Boeotia from Attica, and on the southern edge of the Boeotian plain. It played an important role in Greek myth, as the site of the stories of Cadmus, Oedipus, Dionysus and others...

 tradition that the river Cephissus formerly flowed under the a mountain and entered the sea until Heracles

Heracles

Heracles ,born Alcaeus or Alcides , was a divine hero in Greek mythology, the son of Zeus and Alcmene, foster son of Amphitryon and great-grandson of Perseus...

 blocked the passage and diverted the water into the Orchomenian

Orchomenus

-Greek mythology:*Orchomenus, a king, the father of Elara*Orchomenus, one of the twenty sons of Lycaon*Orchomenus, son of Zeus and Isonoe, father of Minyas and Kyparissos*Orchomenus, a son of Athamas and Themisto-Ancient Greek geography:...

 plain; but he does not believe it.

Pausanias (10.8.1) also says that the Lilaeans on certain days threw cakes and other customary items into the spring of the Cephissus and that they would reappear in the spring of Castalia

Castalia

Castalia , in Greek mythology, was a nymph whom Apollo transformed into a fountain at Delphi, at the base of Mount Parnassos, or at Mount Helicon. Castalia could inspire the genius of poetry to those who drank her waters or listened to their quiet sound; the sacred water was also used to clean the...

.

The same author names as daughters of this Cephissus:

• the naiad
  Naiad
  In Greek mythology, the Naiads or Naiades were a type of nymph who presided over fountains, wells, springs, streams, and brooks....
  
   Lilaea
  Lilaea
  In Greek mythology, Lilaea was a Naiad of a spring of the same name, daughter of the river god Cephissus.The town of Lilaea in Phocis and the asteroid 213 Lilaea are named after her....
  
   (10.33.4) the eponym of Lilaea at its source,
• Daulis
  Daulis
  Daulis was an ancient Greek city in Phocis.According to Greek mythology, Daulis was the hometown of Tereus. The city is mentioned by Homer and it is said to be named after a nymph Daulis, a daughter of the river-god Cephissus....
  
   (10.4.7) the eponym of the city of Daulis,
• Melaeno (10.6.4) mother of Delphus
  Delphus
  For other uses, see DelphosDelphus or Delphos was a son of Poseidon and Melantho, a daughter of Deucalion, from whom the town of Delphi was believed to have derived its name....
  
   by Apollo
  Apollo
  Apollo is one of the most important and complex of the Olympian deities in Greek and Roman mythology...
  
  , though he also gives two other accounts of Delphus' mother. However one of these alternate versions is that Thyia
  Thyia
  According to a quotation from Hesiod's lost work Eoiae or Catalogue of Women, preserved in the De Thematibus of Constantine Porphyrogenitus, Thyia was the daughter of Deucalion and Pyrrha and mother of Magnes and Makednos by Zeus.In the Delphic tradition, Thyia was also the naiad of a spring on...
  
   daughter of the aboriginal Castalius
  Castalius
  Castalius is a butterfly genus in the family Lycaenidae. They are commonly known as pierrots. This name is also often used for the very closely related genus Tarucus....
  
   was Delphus' mother, almost certainly the same Thyia whom Herodotus
  Herodotus
  Herodotus was an ancient Greek historian who was born in Halicarnassus, Caria and lived in the 5th century BC . He has been called the "Father of History", and was the first historian known to collect his materials systematically, test their accuracy to a certain extent and arrange them in a...
  
   (7.178.1) claims was daughter of Cephissus to whom the Delphians built an altar to the winds and who was eponym of the Thyiads.

A mortal son of Cephissus was Eteocles

Eteocles (son of Andreus)

In Greek mythology, Eteocles was a king of Orchomenus. The local tradition concerning him is preserved in Pausanias' Description of Greece, and runs as follows....

 by Euippe

Euippe

Euippe or Evippe is the name of six women in Greek mythology:*The daughter of Danaus and the naiad Polyxo. She married Imbrus, son of Aegyptus and Caliadne....

 daughter of Leucon son of Athamas

Athamas

The king of Orchomenus in Greek mythology, Athamas , was married first to the goddess Nephele with whom he had the twins Phrixus or Frixos and Helle. He later divorced Nephele and married Ino, daughter of Cadmus. With Ino, he had two children: Learches and Melicertes...

. This Euippe was wife of King Andreus

Andreus

Andreus was the son of the river-god Peneus in Thessaly, from whom the district about Orchomenos in Boeotia was called Andreis. In another passage Pausanias speaks of Andreus as the person who first colonized the island of Andros...

 of Orchomenus

Orchomenus

-Greek mythology:*Orchomenus, a king, the father of Elara*Orchomenus, one of the twenty sons of Lycaon*Orchomenus, son of Zeus and Isonoe, father of Minyas and Kyparissos*Orchomenus, a son of Athamas and Themisto-Ancient Greek geography:...

 and Eteocles inherited Andreus' throne (9.34.9). Eteocles or Eteoclus son of Cephissus is confirmed from Hesiod

Hesiod

Hesiod was a Greek oral poet generally thought by scholars to have been active between 750 and 650 BC, around the same time as Homer. His is the first European poetry in which the poet regards himself as a topic, an individual with a distinctive role to play. Ancient authors credited him and...

's Catalogue (Fr. 26) and Pindar

Pindar

Pindar , was an Ancient Greek lyric poet. Of the canonical nine lyric poets of ancient Greece, his work is the best preserved. Quintilian described him as "by far the greatest of the nine lyric poets, in virtue of his inspired magnificence, the beauty of his thoughts and figures, the rich...

 (Ol. 14). He first made offering to the Charites

Charites

In Greek mythology, a Charis is one of several Charites , goddesses of charm, beauty, nature, human creativity and fertility. They ordinarily numbered three, from youngest to oldest: Aglaea , Euphrosyne , and Thalia . In Roman mythology they were known as the Gratiae, the "Graces"...

 by the side of the river Cephissus.

Cephissus was also father of Narcissus

Narcissus (mythology)

Narcissus or Narkissos , possibly derived from ναρκη meaning "sleep, numbness," in Greek mythology was a hunter from the territory of Thespiae in Boeotia who was renowned for his beauty. He was exceptionally proud, in that he disdained those who loved him...

 according to Ovid

Ovid

Publius Ovidius Naso , known as Ovid in the English-speaking world, was a Roman poet who is best known as the author of the three major collections of erotic poetry: Heroides, Amores, and Ars Amatoria...

's Metamorphoses

Metamorphoses (poem)

Metamorphoses is a Latin narrative poem in fifteen books by the Roman poet Ovid describing the history of the world from its creation to the deification of Julius Caesar within a loose mythico-historical framework. Completed in AD 8, it is recognized as a masterpiece of Golden Age Latin literature...

(3.342), Hyginus

Gaius Julius Hyginus

Gaius Julius Hyginus was a Latin author, a pupil of the famous Cornelius Alexander Polyhistor, and a freedman of Caesar Augustus. He was by Augustus elected superintendent of the Palatine library according to Suetonius' De Grammaticis, 20...

 (271), and Statius

Statius

Publius Papinius Statius was a Roman poet of the 1st century CE . Besides his poetry in Latin, which include an epic poem, the Thebaid, a collection of occasional poetry, the Silvae, and the unfinished epic, the Achilleid, he is best known for his appearance as a major character in the Purgatory...

' Thebaid (7.340), Narcissus' mother being an otherwise unknown naiad named Liriope according to Ovid.