344 CAI.II'OUNIA ACADKMY Ol' SCIENCES. 



ARTHROPODA. 



Class CRUSlACi'lA.' 

 Siil)ci;iss EUCKIJSTACHA. 



Supcrnnlcr V\ K K I I'l.Dl A. 

 Order TIIORACICA. 



Family XC. BAI,AXiI).E. 



Genus Balanus /.inO'r. 



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

 base membranous or calcareous. 



406. Balanus concavus liroan. 



Balanns concavus Bronn, Italians Tertiar-Gebikle (1831) et Leth;ea Geognostica, b, II, 3, 1155 

 (1838), Tab. XXXVI, fig. 12; = B. cylindraccus var. concavus Lam.; = Lcpas 

 tinlinnabidum Brocchi, (^fide Darwin, Monog. Cerripedia, II, p. 235, PI. IV, 

 fig. 4rt-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 pinlc hiirnacle of the west coast. Darwin reports this 

 species as fossil from Coralline crag, England; subappenine fortnations, 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 Dcadman 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). 



^Tbe classification and generic descriptlooB of this class, unless otherwise stated, are from Eastman's Zitfel's " Text.Book 

 of Paleontology.*' 



