NO. 1 fraser: hydroids 49 



Family Synthecidae 

 Genus SYNTHEGIUM 

 Synthecium gracile Fraser 



Synthecium gracile Fraser, Johnson-Smithsonian Hyd., 1937, p. 2. 



Distribution. — Santa Elena Bay, 10-12 fathoms; Port Utria, 20 

 fathoms; Pacora Island, 15-25 fathoms; White Friars, 25 fathoms; 

 east of islands of? Navidad Head, 25-35 fathoms; Santa Maria Bay, 

 10 fathoms; South Bay, Cerros Island, low tide and in 10-15 fathoms. 



Synthecium projectum, new species 

 Plate 11, Fig. 55 



Trophosome. — Short, stout, unbranched colonies arise from a stolon, 

 10 mm. high. The stem is divided into rather long internodes by slightly 

 oblique nodes. There is one hydrotheca to each internode, with a regu- 

 larly alternate arrangement; two successive hydrothecae on the same 

 side are quite distant. Hydrotheca projecting well out from the stem, 

 adhering at the base and about one third of the adcauline side; stout, 

 about half as wide as long, the free portion turning out at an angle 

 of a little more than 45° with the stem. Margin somewhat saddle- 

 shaped, flaring a little. 



Gonosome. — Not observed. 



Distribution. — Bahia Honda, 15-25 fathoms; White Friars, 25 

 fathoms; east of islands off Navidad Head, 25-35 fathoms; Santa Maria 

 Bay, low tide; Thurloe Point, 8-10 fathoms; South Bay, Cerros Island, 

 low tide. 



Synthecium rigidum, new species 

 Plate 11, Fig. 56 



Trophosome. — Colony unbranched, straight and rather rigid, 10 

 mm. high; divided into regular internodes, with one hydrotheca to each, 

 alternating. Hydrotheca nearly as broad as deep, 0.28-0.32 mm., and 

 much the same diameter throughout ; adnate from one third to one 

 half of its length. Margin circular, definitely flaring. 



Gonosome. — Not observed. 



Distribution. — Santa Elena Bay, 10 fathoms; White Friars, 25 

 fathoms; east of islands off Navidad Head, 25-35 fathoms. 



