THE REPRODUCTIVE ORGANS OF KUKENTHALIA BOREALIS. 187 



9. On the Reproductive Organs of the Ascidian Kukenthalia 

 borealis (Grottschaldt). By Dr. Augusta Arnback- 

 Christie-Linde *. 



(Text -figures 1-8.) 

 [Received October 7, 1920 : Eead March 8, 1921.] 



The subfamily of the Polyzoiuw, to which Kukenthalia borealis 

 (Gottsehaldt) has been referred, is regarded as an intermediate 

 group between the Styelidse and the Botryllidse. ' According to 

 Michaelsen f , who has given descriptions of this group of Ascidians 

 in several papers, it comprises about ten genera, distributed in 

 almost every region all over the world. 



In the Arctic region it is represented by a single genus with 

 one species, Kukenthalia borealis. 



The species was first described by Gottsehaldt + under the name 

 of Goodsiria borealis. It was re-described by Hartmeyer§ in 

 ' Fauna Arctica ' under the new generic name Kukenthalia. 



As it thus appears, the species has been the object of thorough 

 examination by several eminent zoologists. However, it has not 

 hitherto been possible, so far as I know, to make out its internal 

 structure, owing to the unsatisfactory knowledge of the repro- 

 ductive organs. 



Gottsehaldt (I. c.) merely writes as follows : " Die Geschlechts- 

 organe liegen in der Tunica (es wurde ein einziges ziemlich grosses 

 Ei gefunden)." 



Two years later Bonnevie !| described a few colonies of the 

 species which had been dredged by the Norwegian Atlantic 

 Expedition. 1876-1878. They were described under the name of 

 Goodsiria coccinea (Cunningham). With regard to the repro- 

 ductive organs, the author states that they "are found in small 

 polycarps in the muscular stratum," a statement which proves 

 to be a mistake. 



Hartmeyer writes (I. c. p. 260) : — " Weiblicher Geschlechts- 

 apparat diffus (grossere und kleinere Eizellen iiberall in den 

 Innenkorper eingestreut sowie in den Blutbahnen der Darm- 

 wandung und der jungen Knospen); mannlicher Geschlechts- 

 apparat bisher nicht nachgewiesen." " Ein besonderes Ovarium 

 ist nach unseren Untersuchungen nicht vorhanden " (I. c. p. 258). 



In the paper of Michaelsen we find the same statement. 



* Communicated by Dr. F. A. Bathek, F.R.S., P.Z.S. 



f Michaelsen, W., " Revision der compositen Styeliden oder Polyzoinen." 

 Mitteilungen aus d. Naturhist. Museum in Hamburg, Jahrgang 21. Hamburg, 

 190 1. 



X Gottscbaldt, R., " Die Synascidien der Bremer Expedition nach Spitzbergen im 

 Jabre 1889." Jen. Z. vol. xxviii- Jena, 1894. 



§ Hartmeyer, R., "Die Ascidien der Arctis." Fauna Arctica, Bd. iii. Jena, 

 1903-1904. 



|| Bonnevie, K., " A.scidim simplices and Ascidice composite. From the North 

 Atlantic Expedition." The Norwegian North Atlantic Expedition, 1876-1878. 

 Christiania, 1896. 



Pkoc. Zool. Soc— 1 92 1 , No. XIV. 1 4 



