Boone, Crustacea, Cruises of "Ara" and "Alva" 281 



station on the Pourtales Plateau, 10 miles south of Key West, 

 Florida, on spines of Dorocidaris (a sea urchin), specimens from 

 a "Blake" station, off Florida, in 195 fathoms on D. abyssicola 

 (A. Agassiz) , and the present series, collected by Mr. Vanderbilt, 

 on sea urchins, from off Sand Key Light, Florida, in 65 and 100 

 fathoms, represent the known distribution of this very beautiful 

 small barnacle. 



Material examined: Ten barnacles sessile on the primary 

 spines of the sea urchin, Cidaris abyssicola (A. Agassiz) , dredged 

 in 100 fathoms, nine miles off Sand Key Light, Florida, March 11, 

 1936. Twenty-five barnacles sessile on the primary spines of 

 fourteen specimens of the identical species of urchin, dredged in 

 65 fathoms off Sand Key Light, Florida, November 25, 1C35 ; both 

 series dredged by the "Alva." 



Discussion: The thirty-five specimens of the present series 

 include representatives of various growth stages of the species, 

 from very young to quite large adults, and correspond in all di- 

 agnostic characters with the excellent descriptions and illustra- 

 tions of the species presented by Dr. Pilsbry. 



References : Verruca nexa alba, Pilsbry, H. A., Bull. 60, U. S. 

 Nat. Mus., 1907, p. 107, pi. 11, figs. 7, 8. 



Verruca alba, PiLSBRY, H. A., Bull. 9, Ibid, 1916, p. 25, pi. 2, figs. 

 1, 1-b, 2. 



