84 



BULLETIN 93, UNITED STATES NATIONAL MUSEUM. 



been in water (Quissett Harbor) some 80 days (about July 1 to Sep- 

 tember 18), the largest are 20 mm. in diameter. Dr. F. B. Sumner 

 has recorded specimens from 20 to 26 mm. in diameter, on the bottom 

 of a whaleboat which had been moored within the inclosure of the 

 pier at Woods Hole from May until November or December, 1908. 

 It appears., therefore, to attain full size in a little over three months. 



BALANU3 IMPROVISUS Darwin. 

 Plate 24, figs. 3-36, 5-5</. 



1854. Balanus improvisus DARWIN, Monograph, p. 250, pi. 6, figa. la-lc, with 

 var. assimilis, p. 250. 



1869. Balanus improvisus, var. gryphicus MUNTER, Mittheil. naturwissensch. 

 Verein von Neu- Pommern und Riigen, vol. 1, p. 1. See METZGER, Nach- 

 richtsblatt d. deutschen malak. Ges., vol. 10, 1878, p. 7-9. 



1897. Balanus improvisus WELTNER, Verzeichnis recenten Cirripedienarten, 

 p. 266. 



1870. Balanus improvisus Darwin, CZERNIAVSKE, Zool. Record, p. 205 (Black Sea). 



Type. British Museum, from Kent, England. 



Distribution. Scotland to the ocean coast of France; Nova Scotia 

 to southern Patagonia, Guayaquil, west -Colombia, attached to wood, 

 shells, rocks and ships' bottoms, from low tide to 20 fathoms depth 

 (Darwin). Black Sea and Red Sea (Weltner). 



