HJALMAR BROCH. 



[REP. OF THE "MICHAEL SARS" NORTH 



Thecocarpus Nutting. 

 Thecocarpus myriophyllum (Lin.) Nutting. 



West of Gibraltar (Stat. 23) a single fertile colony 

 from 1215 metres; near Cape Bojador (Stat. 38) a single 

 sterile colony from 77 metres. 



Cladocarpus (Allman). 

 Cladocarpus (?) Hjorti n. sp. 



Near Gibraltar (Stat. 20) in 141 metres, some large 

 sterile colonies. 



Some colonies of a large Aglaopheniid apparently 

 belonging to an unknown species, were taken at Station 

 20, but as they are destitute of gonangia, their position 

 cannot be settled with certainty. 



The slender colonies are very large, exceeding half 

 a metre in height, and are only sparingly branched. The 

 hydrocladia attain a length of 45 mm, and are inserted 

 on the stem at intervals of 1 mm. or more. The greater 

 part of the stem is composed of several tubes, but in the 

 outer parts the fasciculation ceases, and the very top of 

 each branch shows a monosiphonic hydrocaulus. The 

 primary tube is provided with a single mesial row of large 



Fig. 10. Cladocarpus (?) Hjorti from Stat. 20. a: portion 



of the stem with the top of the first accessory tube (t). 



b: portion of the stem farther down. Side view. * lateral 



holes of the accessory tube. (/ 40). 



sessile nematothecae along its anterior (ventral) side (fig. 

 10); the nematothecae between the insertion of two suc- 

 cessive hydrocladia vary in number from 2 to 7, or even 8. 

 These ventral nematothecae give the hydrocaulus as seen 

 from the side a curiously denticled appearance. Near the 



top (fig. 10, a) the first accessory tube (t) already appears 

 covering the posterior (dorsal) side of the primary tube. 

 Series of holes (fig. 10) are observed on each side of the 

 posterior tube where the walls of the latter meet with 

 those of the primary tube; the holes are connected with 



Fig 11. Cladocarpus (?) Hjorti from Stat. 20. 

 Hydrotheca. (;< 60). 



the lumen of the secondary tube as well as with the sur- 

 rounding medium. A little farther down (fig. 10, b) these 

 peculiarities are still more obvious, but it was impossible 

 to see whether there were any nematocysts in the lateral 

 holes or not. 



The hydrocladia are inserted on the ventral side of 

 the' primary tube; they are directed upwards and outwards 

 and diverge alternately to each side of the mesial plane 

 of the colony. The hydrocladia are not in the lateral 

 plane of the colony as in most other Aglaopheniidae, but 

 are directed more ventrally (anteriorly) than laterally, a 

 fact adding much to the slender aspect of the colonies. 

 The hydrocladia are jointed, and each internode is provided 

 with a hydrotheca and three nematothecae. 



The hydrotheca (fig. 11) is very little compressed late- 

 rally. The margin is provided with a prominent, though 

 rather slender, anterior tooth. Along the sides of the 

 opening slight sinuations only are seen, and these disap- 

 pear near the adnate posterior part of the hydrotheca. 

 A thickening of the inner side of the thecal wall (an 

 intrathecal ridge) in traced anteriorly almost midway be- 

 tween the top of the low mesial nematotheca and the 

 margin of the hydrotheca. - The supracalycine nemato- 

 thecae are small. 



The septal ridges vary in number. Generally we find 

 two ridges at the base of the supracalycine nematotheca, 

 and sometimes an indistinct third one is observed a little 

 farther down the upper part of the posterior thecal wall. 

 At the lower part of the thecal wall we find three to five 

 septal ridges, besides a strong one at the proximal end of 

 the internode. The adnate wall of the hydrotheca as seen 

 from the side consists of two parts: a distal part terminating 

 in the lumen of the hydrotheca, and a proximal or basal 

 part, ending nearer to the posterior side of the hydro- 



