HYDROIDA II 



8i 



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

 margin and are adcaulinally 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. 



n 



h 



Material : 



"Ingolf" vSt. 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 onlv 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 colon}- 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 sarcothecse 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 hydrothecse 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- 

 cothecse 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 

 ^Aglaophcnopsis Verrilti Nutting that it should, for the* present at any rate, be placed near this; the 

 differences consist in the somewhat shorter and broader hydrothecse 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-Kxpedition. V. 7. I] 



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



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



b. Internodium of the hydrocladium with hydrotheca in side- 

 view, c. Frontal view of hvdrotheca and internodium. ( X 60). 



