NO. 3 fraser: hydroids 139 



reach a height of 3 mm. All of the pedicels are regularly corrugated 

 throughout; these may be shallow to give a wrinkled appearance. The 

 turbinate hydrotheca has nine or ten segments in the operculum. 



Gonosome. — The gonangium grows from the stolon, on a short 

 corrugated pedicel; it is large as compared with the size of the hydro- 

 theca, almost 1.0 mm. in length, shaped like half of an ellipse, the distal 

 end being truncated. There is a single medusa in the gonangium, the 

 height being greater than the transverse diameter. The one in the speci- 

 men described has four radial canals and four spherical tentacle bulbs, 

 visible through the gonangium. 



Halecium tenue, new species 

 Plate 20, Fig. 6 



Trophosome. — Colony slender, up to 12 mm. in height; stem usually 

 simple, but occasionally, slightly fascicled ; it does not form a continu- 

 ous axis for the colony. There is a long pedicellate portion for each 

 hydrophore, and then just proximal to the hydrophore another pedicel 

 is given oiif for the next hydrophore. Commonly the hydrophore is dupli- 

 cated one or more times, with a varying length of pedicel between, or 

 a branch, similar to the main stem, may grow out of the hydrophore. 

 There are seldom any nodes or evidences of annulation. The rim of the 

 hydrophore is slightly but distinctly flaring. 



Gonosome. — All of the gonangia that were not empty were female. 

 It may be that male and female are similar in shape and size. The 

 gonangium is biconvex, 0.75 mm. long, 0.5 mm. in the greater diameter, 

 and 0.25 mm. in the lesser, with a very short pedicel. It may appear 

 on the stolon or any part of the stem. 



Ophlodissa alternata, new species 

 Plate 20, Fig. 7 



Trophosome. — Colony reaching a height of 8 mm., but usually much 

 less, with a slight tendency to fasciculation in the larger colonies, grow- 

 ing from an unbranched stolon (in this instance, creeping over the 

 hydroid Lytocarpus philippinus) ; branches, if present, few and scat- 

 tered irregularly. Stem zigzag, as the pedicel of each hydrophore comes 

 out from near the distal end of the previous pedicel, and the pedicels 

 alternate from side to side. Each pedicel has a double annulation near 

 the proximal end; hydrophore distinctly flaring. 



