HYDROIDA II 



121 



Stiffly built, pinnate, dark-brown colonies with undivided branches. The stem, which is mono- 

 siphonic, is divided up into irregular internodia, and has two single longitudinal rows of hydrothecse 

 and two rows of alternating branches; there are three hydrothecae between two successive branches 

 on same side of the stem, the lowest in the branch corner. The branches have two rows of very closely 

 packed hydrothecae, the hydrothecse in the single longitudinal rows have their oral parts alternately 

 turned to either side, making a distinct approach to quadriserial arrangement, and the branches thus be- 

 come almost quadrilateral in section. The hydrothecse are small, entirely embedded, without any free 

 distal part of the adcauline wall; the opening margin forms an adcauline sinus, in which the large 

 opercular plate is attached. The hydrotheca opening is comparatively very large. 



200 m. _ . — boom. tooom. 2 000 m 



Fig. LXIV. The occurrence of Abietinaria ftj/iisca in the Northern Atlantic. 

 (In British waters the data are somewhat vague, but note a rather common occurrence). 



The gonothecae are set on the upper side of the branches. They are pear-shaped, with 

 short stalks. 



Material : 



•'Ingolf" St. 55 63°33' N., i5°02' W.; depth 316 fathoms, 5,9° 

 The Faroe Islands: 7 miles N. by E. of Myggenaes point, depth 57 fathoms 

 6 — N. by W. of Store Kalso, — 60 — 



Deep hole at north point of Nolso, — 100 — 



16 miles E. by S. of south point of Nolso, — 80 — 



It is uncertain whether this species can be allowed to retain its place in the genus Abietinaria. 



The Ingolf- Expedition. V. 7. 1 6 



