REPORT ON THE SIPHONOPHORiE. 249 



form prominences (" erbsengrosse Anschwellungen "), probably the basal parts of the 

 detached and lost bracts. The siphons themselves (in a strongly contracted state) 

 attain a length of 50 to 60 mm. and a thickness of 30 mm., and are therefore 

 much larger than in any other known Siphonophoras ; in the fully expanded state they 

 may have a length of half a metre or more. The basal half of the spindle-shaped 

 siphons is distinguished outside by the possession of two opposite lateral wings or crests. 

 Their whole inside is covered with innumerable small villi, which replace the wanting 

 hepatic ridges. The gonodendra, which seem to alternate with the siphons, are elegant 

 oblongish bunches 70 mm. to 80 mm. in length and 10 mm. to 15 mm. in breadth, 

 attached directly to the trunk by thin tubular pedicles of nearly the same length. 

 Each gonodendron is richly branched, and bears many hundreds of pediculate ovate 

 gonophores, about 1 to 1*5 mm. in diameter. The bad state of preservation did not allow 

 the recognition of their structure ; but all the gonophores in each gonodendron seemed to 

 be of the same sex. 



Unfortunately the bracts as well as the nectophores were all detached and lost in 

 the fragments of the corm described by Studer ; but the great facility with which these 

 parts are detached in all Forskalidae explains their complete absence sufficiently ; and the 

 more so, as the mode of capturing this gigantic deep-sea form, brought up on a grapnel 

 from depths of 1000 to 1800 fathoms, must have injured the delicate corm in the most 

 violent manner. The tentacles which were originally attached to the base of the siphons 

 were also found separate from them ; they bore a series of tentilla, with ovate cnidosacs 

 12 to 15 mm. in length and 4 to 5 mm. in thickness; their spiral cnidoband had 

 numerous turnings. Similar to the siphons, but of half their size, and provided with 

 two larger longitudinal wings, were detached bodies, which Studer has described as 

 "bracts" (loc. cit., p. 20, Taf. iii. fig. 25) ; they are probably cystons. 



Probably to the same genus belongs a gigantic deep-sea form, the detached siphons 

 of which Fewkes has described in 1886 as Pterophysa grandis, taken from a depth of 

 2109 fathoms in the Gulf Stream (45, Nr. xxxvi. p. 960, pi. x. figs. 1-3). Scattered 

 fragments and detached parts of another large Forskalid, probably closely allied, were 

 found in a bottle in the Challenger collection taken in the South Atlantic (Station 

 323, depth 1900 fathoms). It may be called provisionally Bathyphysa gigantea. 



Family XV. Nectalid^e, Haeckel, 1888. 



Nedalidx, Hkl., System der Siphonophoren, p. 41. 

 Definition. — Physonectse polygastricse, with a short vesicular stem of the siphosome, 

 bearing numerous siphons, palpons, and bracts, each siphon provided with a branched 

 tentacle. Nectosome with two or four rows of nectophores. Pneumatophore with radial 

 pouches. 



(ZOOL. CHALL. EXP. — PART LXXVII. — 1888.) Hhhh 32 



