LEPTOMEDUS.E — CAMPALECIUM, STAUROPHORA. 291 



Gonosome. — Medusoid 2 to 5 linear series. Medusae each with 4 tentacles, 2 large, 2 

 small. Manubrium conical. Lithocysts ( ?) It is doubtful whether medusae be seMljee^or not. 

 The only species is Campalecium medusiferum Torrey, H. B., 1902 (loc. at., p. 48,^pKft;e;„3, 

 figures 26 to 29), from Long Beach, California. The free medusae are not known. This is 

 the only Halecium-like hydroid which produces medusae in its gonangia. 



Genus STAUROPHORA Brandt, 1834. 



Staurophora, Brandt, 1834, Prodromus animalium ab H. Mertensio, etc., separate, p. 30; 1838, Mem. Acad. Imperiale des Sci. 

 St. Petersbourg, Sci. Naturelles, ser. 6, torn. 4, p. 399. — Agassiz, L., 1849, Memoirs Amer. Acad., New Series, vol. 4, p. 300. — 

 Lesson, 1843, Hist. Zooph. Acal., p. 297. — Agassiz, L., 1862, Cont. Nat. Hist. V. S., vol. 4, p. 351. — Agassiz, A., 1865, 

 North Amer. Acal., p. 136. — Haeckel, 1879, Syst. der Medusen, p. 148. — Hartlaub, 1897, Hydromeduscn Helgolands, 

 p. 484. — Wagner, 1885, Wirbellosen des Weissen Meeres, p. 80. 



Staurostoma (in part), Haeckel, 1879, Syst. der Medusen, p. 130. 



Staurostoma (young stage), Haeckel, 1879, Syst. der Medusen, p. 130. 



Staurostoma, Maas, 1893, Ergeb. der Plankton Exped., Bd. 2, K. c, p. 65. — Linko, 1900, Mem. Acad. Imp. Sci. St. Petersbourg, 

 ser. 8, tome 10, No. 3, p. 4. 



Staurostoma= Staurophora, Birula, 1896, Annuaire Musec Zool. Acad. Imp. Sci. St. Pt'tersbourg, tome I, p. 342. 



Staurophora— Staurostoma, Browne, 1907, Annals and Mag. Nat. Hist., ser. 7, vol. 20, p. 469. 



GENERIC CHARACTERS. 



Eucopidae in which the mouth is a cruciform, gutter-like slit extending down the 4 radial- 

 canals nearly to the bell-margin. The 4 radial-canals are therefore open grooves bordered 

 on their edges by curtain-like walls. These "stomach" walls contain the gonads. The radial- 

 canals may give rise to numerous short, blindly-ending side branches. There are numerous 

 tentacles, lithocysts, and ocelli. 



The lithocysts in Staurophora are so minute and so deeply sunken within the ectoderm of 

 the subumbrella side of the velum, that they were overlooked until Linko, 1900, announced 

 that he had discovered them, upon sectioning the medusa. Many and possibly all of the mar- 

 ginal clubs seen in well-grown specimens of Staurophora develop ultimately into tentacles. 



The type species of this genus is Staurophora mertensii Brandt, of the Aleutian Islands, 

 North Pacific. This medusa appears to be an Arctic species and to be identical with Stauro- 

 phora laciniata L. Agassiz, of the North Atlantic. "Staurostoma arctica" of Haeckel appears 

 to be a young or abortive stage of Staurophora laciniata, in which the radial-canals have 

 folded or frilled margins instead of feathered edges as in Staurophora. "Staurostoma" is also 

 said to have a mouth which extends only part way down the radial-canals instead of reaching 

 almost to the bell-margin as in Staurophora. The Staurophora of the New England coast 

 passes through a "Staurostoma" stage. Haeckel's single specimen of Staurostoma arctica is 

 described as being larger than Staurophora, but possibly it was abortive in the development of 

 its mouth parts and radial-canals. 



Haeckel places "Staurostoma" among the Thaumantiadae, and Staurophora among his 

 Cannotidae, thus widely separating that which I believe to be the young from the adult medusa. 

 Linko, 1900, finds that "Staurostoma" has marginal lithocysts. It must apparently therefore 

 be classified among the Eucopidae, although Browne failed to find lithocysts in the Antarctic 

 Staurophora. 



Staurophora bears a close superficial resemblance to Ptychogena but is distinguished at 

 once by the ocelli on the velar sides of the tentacle bulbs, these being absent in Ptychogena. 



Staurophora mertensii Brandt. 

 Plate 26, figs. 4-9 (Vol. 1). 



Staurophora mertensii, Brandt, 1838, Mem. Acad. Imp. Sci. St. Petersbourg, Sci. Nat., Ser. 6, tome 4, p. 400, taf. 24, 25. 



Staurophora laciniata, Agassiz, L., 1849, Memoirs American Academy, New Series, vol. 4, p. 300, plate 7, figs. 1-15. — Stimpson, 

 1853, Marine Invert. Grand Manan, p. 11. — Agassiz, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 351. — Agassiz, A., 1862, 

 Proc. Boston Soc. Nat. Hist., vol. 9, p. 90, figs. 1-3; 1865, North Amer. Acal., p. 136, figs. 2150-219.— Hartlaub, 1897, 

 Wissen. Meeresuntersuch. Helgoland (Hydromde. Helgolands), Heft 1, Abt. 2, p. 484, taf. i6r, fign. 5, 6, 9, 10; taf. 22, 

 fig. 2. — Wagner, 1885, Wirbellosen des Weissen Meeres, p. 80, taf. 4, fign. 14-20. — Hargitt, 1902, American Naturalist, 

 vol. 36, p. 553. 



Staurophora keithii, Peach, 1867, Journ. Roy. Inst. Cornwall, vol. 2, p. 358, plate 2. 



Staurosotoma laciniata-*- Staurophora mertensii+ Staurostoma arctica, Haeckel, 1879, Syst. der Medusen, pp. 130, 131, 149. 



Staurostoma laciniata, Hargitt, 1904, Bull. U. S. Bureau of Fisheries, vol. 24, p. 43, 1 fig. 



Staurophora mertensi, Bedot, 1905, Revue Suisse de Zool., tome 13, p. 147 (review of all papers to 1850). 



