NO. 1 FRASER : HYDROIDS 53 



Distribution. — Braithwaite Bay, on coral at low tide; Banks Bay, 

 low tide; reef north of entrance to Tagus Cove, low tide; South Sey- 

 mour Island, low tide; Santa Maria Bay, low tide; Thurloe Point, 

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



Sertularella tenella (Alder) 



Sertularia tenella Alder^ Cat. Zooph. Northumberland, 1857, p. 23. 

 Sertularella tenella Hincks, Br. Hyd. Zoophytes, 1868, p. 242. 



Distribution. — North of Wenman Island, 100-150 fathoms; Tagus 

 Cove, 30 fathoms; Cartago Bay, 32 fathoms; between Charles and 

 Indefatigable islands, 60 fathoms; Santa Elena Bay, 10-12 fathoms; 

 La Plata Island, 45-55 fathoms; Secas Islands, 25 fathoms. 



Sertularella ttirgida (Trask) 



Sertularia turgida Trask^ Proc. Cal. Acad. Sc, 1857, p. 113. 

 Sertularella turgida Nutting, Am. Hyd., Part II, 1904, p. 95. 



Distribution. — Santa Maria Bay, low tide; Thurloe Point, 8-10 

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



Genus SERTULARIA 



Sertularia anceps, new species 

 Plate 13, Fig. 61 



Trophosome. — Colony slender, up to 40 mm., with opposite branches 

 similar to the main stem; sometimes only one of the pairs of branches 

 is developed ; stem divided regularly into internodes. Branches given 

 off almost at right angles, a distinct constriction at the base of each. 

 Hydrothecae placed so that the pair is separated almost equally at each 

 margin ; no front and back distinction ; they are near together for about 

 one third of their length and then turn outward rather abruptly, so 

 that the distal portion of the hydrotheca is nearly at right angles to the 

 stem. Margin with three teeth, operculum with three flaps. 



Gonosome. — Not obsei"ved. 



Distribution. — Santa Elena Bay, 10 fathoms and on drifting Sar- 

 gassum; Secas Islands, 15 and 25 fathoms; Isabel Island, 10-25 fath- 

 oms; oil Thurloe Point, 8-10 fathoms; South Bay, Cerros Island, 10-15 

 fathoms. 



