| Polycera quadrilineata Müller, 1776 Fourline nudibranch | 
|   | 
| photo by 
	Coudre, Christian | 
| Family: | Polyceridae () | |||
| Max. size: | ||||
| Environment: | benthic; marine | |||
| Distribution: | Eastern Atlantic, Western Indian Ocean and the Mediterranean. | |||
| Diagnosis: | ||||
| Biology: | Found intertidally on the underside of rocks among arborescent bryozoans (Ref. 866). | |||
| IUCN Red List Status: | Not Evaluated (N.E.) Ref. 123251) | |||
| Threat to humans: | ||||
| Country info: |  | |||