HYDROIDA II 



8l 



proximal sarcotheca does not reach up to the base of the hydrotheca; all the sarcotheca; have a smooth 

 margin and are adeanlinally split. The length of the hydrotheca is about three-fifths that of the inter- 

 nodium. The hydrotheca is of extremely slender build, not laterally compressed, somewhat expanded 

 towards the opening; the opening margin is quite smooth. Numerous small inner ribs are found in 

 the internodia along the hydrotheca wall; a rib also forms the lower boundary of the proximal 

 sarcotheca. 



f\ 



f\ 



J 



Material : 



"Ingolf" St. 81 6i°44' N., 27°oo' W., depth 485 fathoms, 6,i°. 



Of this remarkable species we have only a 

 single quite small colony, the height of which amounts 

 to only about 2 cm. above the close rootlike net- 

 work by which it was attached. The upper 6 mm. 

 bear the hydrocladia, two fairly long on each side, 

 and there is also, at the top of the colony on the 

 left side, a third hydrocladium where the hydrotheca 

 no 2 is still only indicated. On the lower part of 

 the stem there is a secondary tube, which creeps 

 upward along the lower 7 mm. of the primary, show- 

 ing that the fully grown colony will exhibit a poly- 

 siphonic stem. The primary tube differs from that 

 of most other species in the arrangement of the sar- 

 cothecae (fig. XLII «); paired cauline sarcotheca; are 

 lacking, but each internodium has three unpaired 

 sarcothecse; the two lower in the median line one 

 above the other, and the third in the corner at the 

 upper side of the apophyse. 



The hydrotheca; are very characteristic (fig. 

 XLII 6, c), in appearance not unlike a slender quiver, whence the species has been named pharetra. The 

 opening margin is quite smooth, without indication of teeth or irregularities. The supracalycine sar- 

 cotheca; project somewhat up beyond the hydrotheca opening. The proximal sarcotheca is separated 

 by a quite considerable interval from the hydrotheca. 



As no indications of gonangia have yet been found, the systematic position of the species 

 cannot yet be determined with certainty. It presents, however, a so considerable resemblance to 

 Aglaophenopsis Verrilli Nutting that it should, for the present at any rate, be placed near this; the 

 differences consist in the somewhat shorter and broader hydrotheca; of the latter species, where the 

 opening is furnished with teeth, as also in the much shorter distance from the hydrotheca to the 

 proximal sarcotheca. The species is therefore placed with a query in the same genus, under the name 

 of Aglaophenopsis (?) pharetra. On the other hand, it also resembles not a little certain Cladocarpus 



The Ingolf-E\pedition. V. 7. II 



Fig. XLII. Aglaophenopsis (?) pharetra from "Ingolf ' St. Si. 



a. Internodium of the primary eauline tube with the apophyse. 



b. Internodium of the hydrocladium with hydrotheca in side 

 view. c. Frontal view of hydrotheca and internodium. ( X 60). 





