344 CALIFOKNIA ACADEMY OF SCIENCES. 



ARTHROPODA. 

 Class CRUSTACEA/ 



Subclass EUCRUSTACEA. 



Superorcler CIRRIPEDIA. 



Order THORACICA. 



Family XC. BALANID.E. 



Genus Balanus Lister. 



Shell low, conical or cylindrical, composed of six pieces. Opercular plates subtriangular; 

 base membranous or calcareous. 



406. Balanus concavus Bronn. 



Balanus co7icavus Bronn, Italiens Tertiar-Gebilde (1S31) et Lethaea Geognostica, b, II, 3, 1155 

 (1838), Tab. XXXVI, fig. 12; = B. cylindraceus var. concavus Lam.; = Lepas 

 tintinnabuhmi Brocchi, {^fide Darwin, Monog. Cerripedia, II, p. 235, PL IV, 

 fig. 4a-4<?, 1854). 



Shell longitudinally striped with white and pink, or dull purple, sometimes wholly white; 

 scutum finely striated longitudinally; internally, adductor ridge very or moderately prominent. 



This is the common 2)ink barnacle of the west coast. Darwin reports this 

 species as fossil from Coralline crag, England; subappenine formations, near 

 Turin, Asti, Colle in Tuscany; Tertiary beds near Lisbon; Tertiary beds, 

 Williamsburg and Evergreen, Virginia; Maryland. 



Sometimes found in the upper San Pedro series of San Pedro, Los Cerritos, 

 Crawfish George's, and Deadman Island; also reported from the lower San Pedro 

 series of San Pedro. Found in the Pliocene at Packard's Hill, Santa Barbara; and 

 at Puss School, San Diego; in the Pleistocene at Barlow's ranch, Ventura; and at 

 Spanish Bight and Pacific Beach, San Diego. 



Living. — Panama; Peru; San Pedro, California; Philippine Archipelago; 

 Australia (Darwin). 



Pleistocene. — San Pedro (Arnold). 



' The classification and generic descriptions of this claas, unless otherwise stated, are from Eastman's Zittel's "Text-Book 

 of Paleontology." 



