206 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



nyms, thus indicating that his form is not new and lastly he is 

 " disposed to suggest " that it be designated as a new species. I can 

 see no essential difference between Stegopoma gracilis and medusi- 

 fo?vnis and have therefore listed the latter as a synonym. 



Localities. — Dredging station 5168, Sulu Archipelago, Tawi Tawi 

 group, Observation Id., 4° 56' 30" N., 119° 45' 40" E.; depth, 80 

 fathoms. Station 5413, between Cebu and Bohol near Lauis Point, 

 10° 10' 35" N., 124° 3' 15" E.; depth, 42 fathoms. Growing on 

 AcryptolaiJa normani, a new species presently to be described. 



STEGOPOMA DIMORPHA, new species 

 Plate 40, figs. 1, 2, 3 



Trophosome. — Colony not parasitic as in other species of the genus 

 but branching in form and attaining a total height of 9 cm. Stem 

 and main branches fascicled much as in S. fasciata (Johnston). 

 Main branches irregularly disposed, but the ultimate branches are not 

 fascicled and are quite irregularly alternate, with rarely somewhat 

 indefinite nodes, and often annulated proximably. Pedicels of vary- 

 ing length, some being longer than the hydrothecae and others quite 

 short so that the hydrothecae are practically sessile, but not actually 

 so. The pedicels may be ringed or annulated throughout, quite 

 smooth throughout, annulated proximally or annulated distally; 

 but this latter condition is quite rare. Hydrothecae very large, 

 tubular, slender, measuring as much as two mm. in length and 0.5 

 mm. in diameter. The margin is beveled on two sides so that the 

 pleated operculum is in the shape of an " A " tent, a character of 

 the genus. There is an evident diaphragm near the bottom of the 

 hydrotheca. 



Hydranths. — Well shown in the specimen described. The pro- 

 boscis is not strictly conical as is usual in the genus, but approaches 

 the trumpet shape of the Campanularidae, being often wider at its 

 distal end, although it does not have the outward curve of the 

 typical campanularian. There are usually about 16 tentacles, 

 although these vary considerably in number. 



Gonosome. — Gonangia about the same size as the hydrothecae and 

 much the same shape, almost sessile, walls very delicate and trans- 

 parent, so that the structure of the operculum is hard to make out, 

 but it is of the "A" tent type. The blastostyle bears seven develop- 

 ing medusae in fully formed examples. The sex products are not 

 developed sufficiently to disclose ova or spermatozoa. This type of 

 gonangium is usually borne on the ultimate branches and not on the 

 main stem or larger fascicled branches. The second type of gonan- 



