HTDROIDS OF EASTER?^ CANADA 



171 



Dipha.sia rosacea (Linnaeus). 



Trophosome. Colony delicate; branching irregu- 

 lar; hydrothecae opposite, long and slender, Avith at least 

 the distal third free; margin sinuous. 



Gonosome. Male gonangium long and slender, 

 with tubular neck; female gonangium larger, pyriform, 

 distally terminating in two long and six shorter, pointed 

 lobes, the shorter ones curved to the centre; an internal 

 marsupium present. 



No. 81. 

 Diiihasia rosacea. 



Diphasia tamarisca (Linna-us). 



Trophosome. Stem, branches and hydrotheciP very 

 stovit; hydrothecae sub-opposite, nearly one-half free; 

 three low elevations are present on the margin. 



Gonosome. Gonangia both male and female wit^^ 

 one diameter greater than the other, obovate, spiny, the 

 female with lobes forming coarse serrations as well, the 

 two distal lobes mixch elongated. 



Genus IIvdkallmama. 



No. 82. 

 Diphasia tamarisca. 



Trophosome. Hydrothecae in groups on the side of the branches, their bases in 

 line but the distal ends curved alternately to right and left ; operculum of one 

 adcauline flap. 



Gonosome. Gonangia without spines or internal marsupium. 



HydraUmania falcata (Linnaeus). 



Trophosome. Colony long and slender; main 

 branches spirally arranged and of much the same 

 length; hydrothecae tubular or very slightly urceolate, 

 arranged in a row on one side of the branch, bases in 

 line, distal portions turned alternately to right and 

 left, five or six to an internode. 



Gonosome. Gonangium oval, with tubular neck, 

 smooth or with indistinct longitudinal lines. 



No. 83. 

 HydraUmania falcata. 



Genus Selagixopsis. 



Trophosome. Hydrothecae arranged in more than two longitudinal rows, at least 

 on the branches. 



Gonosome. Gonangia oval or obovate, smooth or neai'ly so. 



