JÄDERHOLM, EXOTIC HYDROIDS IN THE SW. ZOOL. STATE MUS. 5 



Sertularia decipiens Lev. 



This species is only kiiown from the foUowing locality 

 and the material is certainly collected at the same time as 

 the original specimen described by Levinsen, from which the 

 colonies examined only differ by their size. Thus the largest 

 colonies attain a height of 28 mm. Levustsen says that this hy- 

 droid is collected at a depth of only 1 fathom, but according 

 to the label, the material has been found in 1 — 5 fathoms. 



Locality: East India, Paumben, Apr. 1889 (Dr. K. Fri- 

 stedt). Represented in numerous sterile colonies. 



Sertularia tubuliformis (Marktanner). 



The specimens examined by myself agree exactly in size 

 as well as in habit and character with the forms of this species 

 from Madagascar and Japan which I have had occasion to exa- 

 mine. Gonothecae not present. 



Locality: The Pacific Ocean, San José South of Panama, 

 2^4 1852 (Eugenie-Exped. ) ; West India, St. Thomas, 5 fathoms 

 (Collector unknown). Several specimens, partly covered mth 

 Diatoms and Bryozoa. 



Sertularia marginata (Kirchp.) 



Locality: West India, St. Barthelemy at a depth of 12 — 18 

 fathoms. Sterile specimens on seaweed. (Dr. A. Goes). 



Sertularia trigonostoma BusK. Pl. 2, Fig. 4. 



This species is represented in a single fragment 3 cm in 

 length, forming the distal portion of a bigger colony. Stem 

 monosiphonic, closely pinnat e. Pinnae regularly alternate of 

 rather variable lengths, some of them terminating in tendrillike 

 filaments. The internodes are short, and separated from 

 each other by oblique joints, each one bearing two hy dr o - 

 thecae. Hydrothecae subalternate in contact in front, widely 

 separated behind, ovate, contracted towards the distal end, 

 only a small portion free. The length of the hydrothecae, 

 0,224 — 0,256 mm, greatest breadth about 0,130 mm. The in- 

 ternodes are more elongated than in the specimen fignj.'ed 

 by Bale. 



Locality: The Indian Ocean, between Batavia and Singa- 

 pore, 1853 (Eugenie-Exped.). 



