Abnormal Delivery (kêloô)
PERO KELOUSE (Celusa) was the Naiad-nymph of the springs of the river Asopos in Sikyonia (southern Greece). She was the mother of the river by the god Poseidon. Pero was probably numbered amongst the Okeanides (Oceanids)--the nymphs of fresh water.
Pero's son Asopos was often portrayed as a lame, hobbling god whose stream ran dry in summer. This explains her two names--Kelousa was derived from the Greek word kêloô meaning "to have an abnormal delivery" and Pero from pêroô "to make lame."
PERO (Pêrô). The mother of the river god Asopus by Poseidon. (Apollod. iii. 12. § 6.)
Source: Dictionary of Greek and Roman Biography and Mythology.
CLASSICAL LITERATURE QUOTES
Pseudo-Apollodorus, Bibliotheca 3. 156 (trans. Aldrich) (Greek mythographer C2nd A.D.) :
"The Asopos (Asopus) river was born of Okeanos (Oceanus) and Tethys, or, according to Akousilaos (Acusilaus) [poet C6th B.C.], of Pero and Poseidon, while others say of Zeus and Eurynome."
Pausanias, Description of Greece 2. 12. 4 (trans. Jones) (Greek travelogue C2nd A.D.) :
"Asopos (Asopus), said to be the son of Kelousa (Celusa) and Poseidon, discovered for him [Aras the first king of Sikyonia] the water of the river which the present inhabitants call after him Asopos."
- Apollodorus, The Library - Greek Mythography C2nd A.D.
- Pausanias, Description of Greece - Greek Travelogue C2nd A.D.