8 ARKIV FÖR ZOOLOGI. BAND 13. N:0 3, 



two to each internode, rising from small projections, one being 

 above and the other below the hydrotheca. The former is 

 small, 0,038 — 0,047 mm long, the latter much longer and mea- 

 sures in length 0,085 — 0,094 mm. Gonothecae unknown. 



A very beautiful hydroid especially characterized by its 

 big, triangulär teeth at the hydrotheca margin. 



Locality: Coast of Brazil, South of Pernambuco, 9° S. Lat., 

 at a depth of 18 fathoms, 1852 (Capt. Verngren). Several 

 colonies growing on seaweed. 



Plumularia setacea (Ellis). 



Localities: Patagonia, Bahia Inutile and Lennox Co ve, 

 10 — 20 fathoms; Lennox Island, 10 — 25 fathoms, several 

 sterile specimens on seaweed (Swed. Exped. to Patagonia 1896). 

 The Indian Ocean, Java Sea, small, undeveloped specimens 

 on corals. (CoUector unknown.) 



Plumularia dendritica Nutt. 



Localit}^: West India, Anguilla, 50 — 100 fathoms. (Dr 

 A. GoÉs.) Only one sterile fragment. 



Aglaophenia delicatula (Busk) Pl. 2, Fig. 7. 



Is found in numbers of unbranched colonies up to 4 cm high. 

 Stems monosiphonic, without hydroclades in proximal portion. 

 The median tooth of the hydrotheca is narrow and generally 

 somewhat recurved towarcls the margin. On either side of this 

 tooth there are two broader, triangulär teeth, and behind the 

 second sometimes a slight undulation. The median sarcotheca 

 reaches up to the margin of the hydrotheca, or nearly so. 

 The length of the hydrotheca is 0,235 — 0,244 mm and breadth 

 at margin 0,132 — 0,141 mm. Corbulae wanting. 



Locality: East India, Paumben, at a depth of 1 — 5 fa- 

 thoms, Apr. 1889 (Dr. K. Fristedt.) 



Aglaophenia postdentata Bill. Pl. 2, Fig. 8. 



As regards the size of the internodes and the hydrothecae 

 the colonies are more delicate than the specimens described 

 by BiLLARD. The dimensions are: The internodes of the hy- 

 droclades 0,216 — 0,22G mm in length, about 0,037 mm in breadth; 



