167 



Virgularia elongata. — Colony long, slender. Stem flexible and 

 elastic to some extent even in the dried state ; at the base attenu- 

 ated and cylindrical, above thicker and grooved, somewhat sub- 

 quadrate and marked by numerous fine longitudinal lines ; broken 

 section, radiate as in a belemnite or the spine of an echinoderm. 



Polypiferous lobes exsert, arranged on opposite sides and alter- 

 nating ; below very small, and with a groove between the two se- 

 ries. Each lobe has ten or twelve fusiform translucent (calcare- 

 ous ?) spines, projecting considerably beyond the margin of the 

 fleshy portion (in dried specimens) of the lobe itself, and each 

 spine appears to correspond to a polype cell, or the boujidary be- 

 tween two. Below the lobes, the fleshy covering is dilated into an 

 elongate fusiform mass. 



Length 18 inches, (upper end broken off from all the specimens); 

 from tip of lower extremity to commencement of lobes, 2-8 in.; 

 width of largest lobes, -12 in.; greatest diameter of stem, -05 in.; 

 width of fleshy expansion below the lobes, '15 m.; smallest diameter 

 above the expansion, -07 in. 



This species has been found only on one occasion in San Fran- 

 cisco Bay, when it was w^ashed up in immense numbers on the 

 beach. 1 have seen a fragment of the same species from Monte- 

 rey, Cal., collected by Dr. Cooper, of the Geological Survey. 



3Iarc1i 11th, 1862. 



President m the Chair. 



Dr. H. Behr read the annexed paper on certain Butterflies of 



California : 



Genus Danais is represented by one species, and this is the most 

 common and -widely spread, Danais archippus Cramer, that on the 

 Western Contment occupies the same position as Danais chrysip- 

 pus, on the Eastern. D. ai-chippus extends from the Northern 

 States through all tropical America to Buenos Ayres, and is 

 equally numerous on the Atlantic as the Pacific side of the conti- 

 nent. The Gcrontageic species, [chrysippus Cramer] that repre- 

 sents our archippus in Asia, Africa and Australia, does not extend 

 so far north as our Danais, and is only occasionally met with in 

 Mediterranean Europe, the northermost locality where it ever was 



