134 



HYDROIDA II 



Iceland: Adalvig (depth not stated). 

 Kara vSea: "Dijmphna". 



Serfiilaria mirabilis is a circumpolar arctic species, belonging to the upper and middle parts 

 of the littoral region. This being the case, it is remarkable to find it, west of the Faroe Islands, in 

 the abyssal region, as taken by the "Thor" (fig. LXXII). Within the waters investigated, Scrtiilaria 

 viirabilis is a species of rare occurrence, otherwise found once at the north-west point of Iceland, and 

 high up in Davis Strait off the west coast of Greenland. 



200 m. «_•_ 600 m. .-_._.-_ looo/n. 



Fig. LXXII. Finds uf Sti iiilan'a mirabilis in the Northern .\tlantic. 



Gen. H yd rail mania (Hincks). 



Upright colonics witli bilateral scs.sile to slightly imbedded hydrothecK. The hydrotheca aper- 

 ture is furnished with two lateral teetli, between which there is a smaller abcauline and a larger ad- 

 caulinc sinus; median teeth lacking. In each of the two sinuses there is fastened a membrane, so 

 that tlie clo.sing a])i)aratns consists of two membranes, the adcauline witli a free distal part. Tlie polyp 

 has a well developed aljcauline l;)lind sack. 



The diagnosis as given coincides with Levinsen's definition (1913 p. 305); we have here 

 merely added the structure of the polyp body. — Levin sen points out that it may be considered 

 doubtful whether a separation between llydrallmauia and Srrtitlaria really is altogether justified, and 

 the observations noted in the following may to a certain degree serve to accentuate the dubiousness 



