Observations on the Attachment of Balanus crenatus Bruguiere Found in the Waters of Puget Sound

It would appear from Darwin's observations upon adult barnacles and those of the writer during the stage of metamorphosis and the process of attachment of B. crenatus Bruguiere that the prehensile antennae of this species were attenuated. Verification for the contention is obtained from the historical data reported by collectors as to the scarcity or absence of the species on arid and rocky beaches, contrasted with its abundant occurrenee where submerged by the tide during its first few hours of attachment. The early development of the cement glands may be to overcome the buoyancy of the water, while the cypri are in their natural habitat; or the ample supply of water may favor the abundant supply of gelatinous material. References in the literature to the recovery of B. glandula Darwin from any stated depth of water are lacking. Camera lucida drawings were made of the Cyclosa of B. crenatus Bruguiere which had been secured to glass slides during their early metamorphosis into the attached barnacle. Thanks are due to Lieutenant E. W. Sylvester, of the U.S. Navy, for his many courtesies during the experimental work; and to Mr. Henry A. Pilsbry, special curator of the department of Mollusea, Academy of Natural Sciences, Philadelphia, who identified the two species submitted to him from adult barnacles taken from the experimental Norfolk Standard steel plates, and from rocks along the shore of Alki Point; to Professors Trevor Kincaid and John Guberlet, of the zoology department of the University of Washington, for their kindness in reviewing the microscopic specimens and data; to Ernest C. Angst, who made the free-hand drawings of the cypri of B. crenatus Bruguiere.