HYDROIDA 11 _- 



iiiteniodiuni, surrounded by a pair of supracalycine sarcothecce on the distal part of the internodiuni 

 and an unpaired median proxiniall}-; between this and the base of the liydrotlieca arises a sarcotheca- 

 bearing branch, which bends forward over the hydrotheca, and has on its con\ex (outer) side a row 

 of sarcothecae. The sarcotheca-beariug- brancli of the basal hxdrothcca developes into a secondar\- 

 hydrocladium of tlie same appearance as the primar\-, but somewhat finer. Also in the exterior 

 sarcothecal branches h}-drotheca; ma>- be developed. The li\-drothccie are fused throughout their 

 basal half with the branch; the distal portion forms an angle with the ba.sal, and widens some- 

 what towards the aperture. The margin is furnished with 9 or 11 teeth; a large median proximal 

 (abcladial), beside this as a rule a couple of smaller ones, then two well marked, and finally there are 

 distally (adcladially) a pair of large teeth of the same size as the proximal, and betw'een them a couple 

 of quite small ones. 



The gonothecse are attached by a short, often almost rudimentar\- stalk to the stem; viewed 

 lateralh', the gonotheca is asymmetricalh- egg-shaped or oval, with a distal lateral opening; seen from 

 the front, they are oval, distalh' often broadly rounded; the aperture is round. At times there nia\- 

 be some approach to formation of an "upper lip" above the mouth. 



Material: 



"Ingolf St. 44 6i''42' N., 9°36' W., depth 545 fathoms 4,8° 

 — - 98 65°38' N., 26°27' W., — 138 — 5,9° 



The new colonies brought home b\ the "Ingolf show that the ffttlicoriKiria pbiiiia Brocli 

 (1903 p. 8) described as distinct species is reallv only a somewhat older stage of Nematocarpus rannt- 

 lifcnis (AUman); we ha\'e now colonies showing the next stages through which they pass over to 

 the possession of secondarily branched hydrocladia (fig. XXXVII a). Here also the species retains its 

 peculiar nude posterior .side, whereas the front appears even more furry than in young colonies. There 

 are certain signs which seem to indicate that a primary hvdrocladium may bear several secondarv 

 ones, Halicor)iaria phiiiia was established chiefly on the strength of the fact that the basal sarcotheca- 

 bearing branch of the hydrocladium has a hydrotheca, whereas the remaining sarcothecal branches 

 lack hydrothecae. The present colonies now show that this was merelv the forerunner of the second- 

 ary hydrocladium, which gradually developes new hydrothecte with sarcotheca-bearing branches out- 

 side the first'. At the same time, however, we find a hydrotheca with its corresponding sarcothecal 

 branch developed at the second, often also at the third hydrotheca, and it is therefore highly j^ossible 

 that in still larger colonies we ma\' also here find developed secondary hydrocladia, showing that a 

 primary h\drocladium can bear several secondarx' ones. 



The gonothecas are incompletely described both by AUman (1874 p. 477) and Broch (1903 

 p. 8) probably from imperfectly developed specimens. The\- are of ver\' peculiar form (fig. XXXVII b). 

 They are attached by a stalk which is not infrequently very short, almost rudimentary. The one 

 (adcauline) side is somewhat flattened and short, the other however, highh' curved and a good deal 

 longer, so that the plane of the aperture is almost or entirely parallel with the longitudinal axis of 



■ In fig. XXXVII (7, the secondary hydrocladium shows only one complete sarcothecal branch (the basal); this is 

 due to the fact that the two next are broken off. Ordinarily, they appear in fully normal development at every single 

 hydrotheca. 



