44 A. C. WALTON 



process of longitudinal division, and Torrey ('98) actually fol- 

 lowed the changes of certain steps of this process in Metridium, 



In working upon jMetridium marginatum, Parker ('99) defi- 

 nitely showed that there is natural normal longitudinal fission, 

 and that the double mouthed and double headed animals were 

 but stages in such a division. Cases where there was circum- 

 stantial evidence of completed division were also found. The 

 division plane was always through primary ectocoels or primary 

 entocoels. Carlgren ('04) believed that, though aboral-oral 

 fission could take place as the result of injury, oral-ahoral fission 

 did not occur, and that the double forms of Metridium studied 

 by Parker and by Torrey were not stages of longitudinal division, 

 but monstrosities developed from partially double embryos, 

 such as are often found in Sagartia and Cribrina species. His 

 further work (Carlgren, '09) only strengthened his belief that 

 fission was due to regeneration after laceration, followed by 

 division, and was not a normal mode of reproduction. 



The material upon which the present article is based consisted 

 of specimens of Actinia bermudensis Verrill obtained at Bermuda 

 during the summer of 1916. I wish here to thank Dr. E, L. 

 Mark, Director, and Dr. W. J. Crozier, Resident Naturalist, for 

 the opportunity to study at the Bermuda Biological Station, and 

 also for their personal assistance. 



Actinia bermudensis Verrill is a small, blood red, shade-loving 

 anemone, living between tide levels, and found only in certain 

 caves along the shores of Bermuda. There are two color phases, 

 perhaps varying enough to be classed as subspecies : one a bright 

 blood red, the other slightly darker and more nearly prune- 

 colored. That the darker colored forms are not merely old in- 

 dividuals is shown by the fact that the embryos of each type 

 are colored exactly like their parents. Mature specimens of 

 either type are from 3 to 4 cm. across the base, and from 2.5 to 

 3.5 cm. across the oral disc, while the column is 4 to 5 cm. in 

 height. The animals are commonly hexamerous, having two 

 pairs of directives, one pair to each siphonoglyph, and from 

 ninety-six to one hundred and twenty mesenteries arranged in 

 three orders. The column wall and both oral and pedal discs 



