14 



HYDROIDA 



If we, therefore, like Kiihn (1913) and Stechow (1913), separate Syucorync as a genus of its 

 owu, there will be insurmountable difficulties about drawing the limits. If, as is done by Stechow, 

 the limit is drawn by the production of free-swimming medusae, Coryiic Lovciii must normally be 

 omitted from the genus Syncorync^ and a species such as Corync Sarsi will j^robably have to be reck- 

 oned sometimes among the Syucorync^ at other times, on the contrary, among the Corync. If, on 

 the other hand, we follow K ii h n and draw the limits of genera between species with eumedusoid 

 gonophores and species having gonophores more strongly reduced, it may be greatly questionable 

 where, for instance, Corync Hincksi and Corync brcvicornis ought in fact to be j^laced. In this case 

 as in others, the more species we learn to know more exactly, the more impossible it proves to draw 

 the limits of genera on the ground of gonophoral conditions. To this must be added that in all the 

 species of Cotyiic or Syncoiync the colonies and the polypes are so uniform as to their appearance, 

 that they cannot with certainty be identified to .species or included under one or the other of the two 

 "genera", if the gonophores are wanting or only little developed. It is, therefore, absurd to insist on 

 drawing an artificial and arbitrary line of distinction, founding on merely biological phenomena of 

 adaption. 



Coryne Sarsii (Loven) Johnston. 



1835 Syncoryna Sarsi/\ Loven, Bidrag til Kannedomen af Sliigterna Cainpainilaria och Syncoryna 



p. 275, pi. 8, fig. 1—6. 

 1847 Corync Sarsi/\ Johnston. A History of the British Zoophytes, p. 43. 

 Pigii Syucorync Sarsii, Ssemundsson, Bidrag til Kundskaben om de islandske Hydroider II, p. 72. 



"The delicately constructed colonies attain to a height of up to 30 mm. The hydrocaulus is 

 wholly irregularly ramified with no distinct main stem; the branches form acute angles with the stem 

 or the main branch whence they proceed; both the stems and the branches are almost entirely 

 smooth with no rings nor wrinkles. The strongly contractile polype, when extended, attains to a 

 length of ujj to 1.5 mm., and is then almost wholly filiform; when contracted, it is oviform or nearly 

 globular. The numerous capitate tentacles are irregularly distributed over the polype. 



The gonophores develop into medusae, which are likely to break away during the greater 

 part of the generative period of the jjolype; the medusa bud developes four tentacles. One or two, 

 more rarely three, gonophores occur simultaneously on the polype". 



Material: 



Iceland, Reykjavik. Shallow water (associated with .small Mytiliis). 



In all probability, Ssemundsson (1902, 1911) is right in including these very delicately con- 

 structed colonies under Coryne Sarsii. The occurrence of the species is boreal. But the possibility that 

 the species is frequently confused with forms nearly related, as yet precludes certain decision as to its 

 distribution. Corync Sarsii is recorded from the coasts of Norway, Bohuslan, Denmark, Helgoland, 

 Great Britain, Iceland, and Northern France. Har tlaub (1905 a) and Jad erholm (1903), though with 

 some doubt, refer some colonies from Tierra del Fuego and from Patagonia to the same species. 



