344 CALIFOllNIA ACADEMY OF SCIENCES. 



ARTHROPODA. 

 Class CRUSTACEA.- 



Subclass EUCRUSTACEA. 



Superorder C I R R 1 1' E U I A. 



Order TIIORACICA. 



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. 



Balamis concavus Bronn, Italiens Tertiar-Gebilde (1831) et Letluea Geognostica, b, II, 3, 1155 

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

 tintinnabuliim Brocchi, {Jide D.A.RWIN, JMonog. Cerripedia, II, p. 235, PI. IV, 

 fig. 4«-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 pink barnacle of the west cQnai. Darwin reports this 

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

 Turin, Asti, CoUe 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 tlie 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; Philij^pine Archipelago; 

 Australia (Darwin). 



Pleistocene. — San Pedro (Arnold). 



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

 of Paleontology." 



