224 DONALD WALTON DAVIS 



March 31, April 30, May 30, and June 29, 1911. I have had 

 opportunities at various other times for less careful observations 

 of localities in which this species occurs. The only recently 

 transformed anemone I have found is a very small and nearly 

 colorless specimen collected at Woods Hole August 4, 1909. 

 This specimen showed no trace of the green color or orange 

 stripes of the column, or of the white line on the oral disc char- 

 acteristic of S. luciae. Whether it belongs to this species, to 

 Cylista leucolena, to Metridium marginatum, or to still another 

 of the species of anemones found at Woods Hole, cannot be 

 stated. In the absence of color it resembles C. leucolena, but 

 we have no reason to believe that at this stage either S. luciae 

 or M. marginatum have developed their characteristic colors. 

 Whatever its proper classification, this anemone was symmetrical 

 and diglyphic and had nearly attained a regular hexameric con- 

 dition of the mesenteries. Each pair of complete non-directive 

 mesenteries, however, had one member incomplete — that mem- 

 ber lying in all cases toward the same end of the chief transverse 

 axis. It is therefore in a stage intermediate between the Ed- 

 wardsia condition and the regularly hexameric form. Even 

 were it determined that this specimen represents a stage in the 

 development of S. luciae, it is by no means certain that the 

 attainment of the condition with six pairs of complete mesen- 

 teries would mark the end of its ontogenetic development. This 

 specimen therefore throws no direct light upon the present 

 problem. It does, however, suggest possible directions in 

 which evidence may be found, and the circumstances connected 

 with it indicate some of the difficulties in the way of a complete 

 solution. The apparent scarcity of developing embryos em- 

 phasizes the impression that the extraordinary method of 

 asexual reproduction is the chief and highly successful means of 

 perpetuating this species and increasing its numbers. 



In Hexactinians six is the most common fundamental number 

 of pairs of complete mesenteries, as two is the typical number of 

 siphonoglyphs. I have shown (p. 220) that such a form is the 

 commonest one among apparently undivided specimens of S. 

 luciae. I have shown further (p. 198) that while successive 



