ARKIV FÖR ZOOLOGI. 



BAND 13. N:o 3. 



On Some Exotic Hydroids in tlie Swedisli 

 Zoological State Museum. 



By 

 ELOF JÄDERHOLM. 



With two Plates. 

 Communicated November 12th 1919 by Hj, Téel and E. Lönnberg. 



A coUection of Exotic Hydroids, which belongs to the 

 Swedish Zoological State Museum, has been placed at my 

 disposal for scientific revision by Professor Dr. T. Odhner, 

 Superintendent of t hat Museum. The material, which has 

 been obtained from the most different parts of the world, con- 

 sists of thirty-two species. Some of these are rather remark- 

 able as for instance Campaniclava clionis Vanhöff., Hale- 

 cium annulatum Torrey, Sertularella diaphana (Btjsk, Allm.), 

 S. formosa Fewkes and others. However, the most interesting 

 hydroid is a Plumularia from the Coast of Brazil, which cannot 

 be identified with any other previously known species. 



Campaniclava clionis Vanhöff. Pl. 1, Fig. 1. 



Hydranths from a creeping hydrorhiza, attaining a height 

 of 1,2 — 1,4 mm and a breadth of 0,7 — 0,8 mm, ovate-fusiform 

 with a wide mouth and a short cylindrical or nearly trumpet - 

 shaped proboscis. A gelatinous envelope around the short 

 hydranth stem, as Vanhöffen states, is not present. Ten- 

 tacles, 8 — 10, of which 7 — 9 are moderately developed, 0,48 — 

 0,G4 mm long, and one of enormous dimensions, four times or 

 more longer and broader than the others. Gonophores, sphe- 



Ärkiv for zoologi. Bd 13. K-o 3, 1 



