.\\THOMKin s K MMMOTOCA. 



10!) 



FIG. 59. Perigonimus "serpens," after Alltnan, in Ray Socjety, 1871-72. 



GENERIC CHARACTERS. 



Tiarina; with 2 long, diamcrrically opposed tentacles, and with more or less numerous, 

 rudimentary tentacles. The basal bulbs of the long tentacles are hollow. The 4 interradial 

 gonads are complexly folded and are found in the ectoderm of the sides of the stomach. The 4 

 radial-canals are broad and flat and there is a well-developed circular canal. The hydroid 

 is Pengonimus. 



There are a numberof species 

 of Pengonimus which probably 

 produce tree f.S'/omo/o, <i i medns.i-. 



'.i/L \.1ia ( '"'/' but the medusa is as yet unknown. 



Such are: Perigontmui .\,lni,-t,/iii 

 Motz-Kossowska, 1905, Archiv. 

 Zool. Exper.. ser. 4, tome 3, p. 72, 

 fig. vi; a red-colored Mediterra- 

 nean hydroid which grows upon 

 Membranipora and is distin- 

 guished by a cup-like expansion 

 of perisarc at the base of each 

 hydranth. The clavate hydranths 

 have about 10 tentacles. Another 

 Mediterranean species is P. nnpol- 

 itiinns of Margin, 1904, Mirth. 

 Zool. Sta. Neapel, Bd. 16, p. 571, 

 taf. 22, fig. 25; also P. steinaehi 

 Jickeli, 1883, Morphol. Jahrb.. 

 Leipzig, Bd. 8, p. 617, taf. 27, figs. 1-9, from Trieste, Adriatic. We present figures of various 

 species of Periganimus which produce free medusae, but in which the sexually mature 

 medusa is undetermined. Perigonimus mitnrcticus (Hickson and Gravely, 1907, National 

 Antarctic Expedition of 1901 04, vol. 3, Nat. Hist., Hydroid Zoophytes, p. 4, plates I and 4) 

 is found attached to the stems of Halecium in depths of o to 130 fathoms in McMurdo Bay. 

 South Victoria Land, Antarctic. It produces fixed gonophores, and is the only form of 

 Perigonimus known from Polar seas. 



Stomotoca dinema L. Agassiz. 



Plate 9, figs. 8 to 10; plate 10, figs. I tci 4. 



Oceania dinema, PF.ROX KT Ltsi'ti R, 1809, Ann. Ju Museum d'Hist. Nat., tome 14, p. 346. EsCHSCHOLTZ, iSi'j. s i. 1, t 



Acalephen, p. 98. 



Suf'henia dinema, FORBES, 1848, British Nakcd-eved MeJus.e, p. 25, plate 2, fig. 4 (Kiel. svn.). 

 tiaphenia titania, Gosst, 1853, Naturalists' Rambles, Devonshire Coast, p. 5X7, plate 26, figs. 7-9. 

 Stomotoca dinema, AC.ASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 347. 

 Amphintma titania, HAF.CKEL, 1879, Syst. der Medusen, p. 50. BEDOT, 1901, Revue Suisse de Zool., tome 9, p. 482; Ibid., 



1905, tome 13, p. 131 (all papers to 1850). 



Amphinema dinema, BROWNE, 1896, Proc. Zool. Soc. London, p. 475. 

 American variety = Stomotoca apicata, L. AGASSIZ. 

 Male: 



Saphenia apifata, McCRADV, 1857, Gymn. Charleston Harbor, p. 129, plate 8, figs. 2, 3. 



Stomotoca aficata, AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 347. AGASSIZ, A., 1865, North Ainer. Acal., p. 168. 

 Amphinema apicatum, HAECKEL, 1879, Syst. der Medusen, p. 50. 

 Female: 



Dinemalel/a cavosa, FF.WKHS, 1 88 1, Bull. Mus. Conip. Zool. at Harvard College, vnl. 8, p. i?i, plate n, figs. 2. 3; plate 4, fig. 



3; 1884, Amer. Naturalist, vol. 19, p. UK, I fig. 



Slomotoca apicata, MAYER, 1900, Bull. Mus. Comp. Zool. Harvard College, vol. 37, p. 3, plate . tigs. 3, 4. H 

 Bull. U.S. Bureau of Fisheries, vol. 24, p. 3?, 2 figs. (Figure .if male is X. apicata, but that of "female" is 

 NUTTING, 1901, Bull. U. S. Fish Commission for 1899, vol. 19, p. 371, fig. 77. 



r, 1904, 

 is S.rugoia.) 



EUROPEAN MEDUSA. 



Bell ^ mm. long and 2 mm. wide, with a narrow, elongate, sharp-pointed apex. 2 long 



tentacles, 2 to 10 times as long as the bell-height. About 24 small tentacle-bulbs. Time aie 



no ectodermal ocelli. Stomach oval, about half as long as the depth of the bell-ca\it\ and 



square in cross-section. 4 well-developed, lanceolate lips. 4 simple, slender radial-canals and 



9 



