188 BR. A. ARNBACK-CHRISTIE-LINDE ON THE 



According to this author, male gonads, as well as female ones, are 

 unknown. And he is of opinion that, with regard to the repro- 

 ductive organs, the genus in question differs from all other 

 Polyzoince, and even from, all other Styelids. 



Nor did Bjerkan * succeed in enlightening us on the matter, 

 though, as he says, he had a great mass of colonies for examination. 



Being occupied with studies on the Northern and Arctic 

 Ascidians belonging to the collections of the Swedish State 

 Museum, I have had opportunities of examining Kiikenthalia 

 horealis. 



My investigations of the species are not yet completed. How- 

 ever, as important facts concerning the reproductive organs have 

 been established, I publish the results already arrived at, hoping 

 that they will augment our knowledge of an organic system of 

 which one has hitherto tried in vain to get a clear conception. 



The material examined was collected off Spitzbergen, Waygat 

 Islands, 60 fathoms, August 1861, and in Ice Fjord, Safe Harbour, 

 30 fathoms, June 1864. I have also had at my disposal a colony 

 from Greenland, 65° 15' N. lat., 53° 30' W. long., collected in 

 June 1883 ; depth 75 fathoms. 



The specimens are preserved in alcohol. 



Spicules. 



Introductorily I will here mention that small spicules occur in 

 the test of Kiikenthalia horealis. 



As is known, the species forms colonies which are massive, 

 usually rounded, and not very large; they are attached by a 



Text-figure 1. 



KiiJcenthalia horealis (Gottscli.). 

 Spicules. X 110. 



narrow base. The zooids are not arranged in systems, and the 

 atrial as v/ell as the branchial aperture of each zooid opens 

 independently on the surface. The test of the colony is well 

 developed, internally and at the base it is soft and gelatinous, 

 externally it is leathery. To this might be added also that the 

 capsules which surround the individuals of the colony are firm 

 and tough. 



The test owes its consistency, partly at least, to the presence of 

 the above-mentioned spicules which are scattered in it. In 

 larger colonies the spicules are abundant, in smaller ones they 

 seem to be less numerous. 



* Bjevkan, P., " Die Asoidien des uordliclien Norvvegeus." Tromso Museums 

 Aarshefter 24-25. 1908. 



