HYDROIDA II j,_ 



Thujaria thuja (Linne) Fleming. 

 1757 Sertularia tliiija^ Linne, Systenia natnrse, Ed. 10, p. 8og. 

 1828 Thujaria thttja, Fleming, A History of British Animals, j). 545. 



Upright colonies, shaped like a bottle-brush, with dark-coloured, distinct monosiphonic hydro- 

 caulus. The branches form an irregular, close double spiral round the indistinctly segmented stem, 

 one branch to each joint. The stem has two rows of hydrothecae; there are normally three hydro- 

 thecse on the stem between two successive branches in the same row, the lowest in the branch corner. 

 The branches form, at their point of origin, almost a right angle with the stem, and are repeatedly 

 divided dichotomously, and curve slightly upward. They are segmented, with a large and varying 

 number of hydrothecse on each joint. The hydrothecae form two opposite rows on the branches; their 

 plane of symmetry coincides with the broad plane of the branch, which is horizontal. The hydrothecae 

 are entirely imbedded in the branches, with no free portion of the adcauline wall; they are subaltern- 

 ately arranged; at the top of the branch they have two lateral teetli, but in course of growth the ad- 

 cauline sinus fills up, normally altogether. The interval between two successive hydrotheca; is about 

 twice the opening diameter of the hydrotheca. The operculum is formed by a round plate abcaulin- 

 ally attached. - . 



The gonothecae are situate on the upper side of the branch, and proceeding from close under 



the base of the hydrothecse. They are oval, without ribs or wrinkles, with a short neck and broad 



round aperture. 



" — I" 

 Material: 



"Ingolf St. 2, 63°04' N., 9=22' W., depth 262 fathoms, 5.3° 



- - 3. 63^35' N., io°24' W., - 



- - 4 64°o7' N., ii°i2' W., 



- - 15, 66° 1 8' N., 25°59' W., - 



- - 34, 65°i7' N., 54°i7' W., - 



- - 51, 64°i5' N., i4°22' W., - 



- - 87, 65°o2,3'N., 23=56,2' W., - 



- - 95, 65^'i4' N., 30^39' W., - 



- - 96, 65°24' N., 29°oo' W., 



- - 98, 65=38' N., 26=27' W., 

 - 127, 66°33' N., 2o°05' W., 



"Thor" 66°i9' N., 23°27' W., 



— 63°46' N., 22=56' W., 



Greenland: Davis Strait, depth 66 — 67 fathoms (without further details) 

 Iceland: Seydisfjord, — 40 — 



5 miles E. of Se\-disfjord, depth 135 fathoms 

 Reykjavik (depth not stated) 



6 miles W. of Iceland, 65=32' N., 24=38' W., depth 22 fathoms 



Danmark Strait 65=39' N., 28=25' W., (depth not stated) 



18* 



