

MOLLUSQUES DU ROUSSILLON 
= Planche 31. 
Classe GASTROPODA (Curier) 
ORDRE |.  Prosobranchiata FAMILLE : Littorinidæ 
Secrion B. Holostomata GENRE : Rissoa 


AN Rissoa variabilis Mühlfeld .var. elongata Monterosato. 
4 = = — (type) 
6, 7, 8, 9: 10, = — — var. brevis Monterosato. 
DD T2 SR LS, — _ ventricosa Desmarest. 
14, _ — — var. subventricosa Cantraine. 
16, 17, 18, 19, 20, —  lineolata Michaud, 
Bucquoy, Dautzenberg & Dollfus,. 

