160 MEDUS.E OF THE WORLD. 



There is considerable variability in coloration among individuals of the same species in 

 many forms of Bougainvillia. The preceding tables present a synopsis of the so-called 

 "species," although it is probable that some of the small medusa listed near the end are 

 only the young of those described higher up on the table. 



Gerd, 1892, finds that the segmentation in the egg of Bouganivillin is at first total and 

 equal and a central segmentation cavity is formed. Then the cells divide tangentially and 

 the nuclei take up a peripheral position. Later there is multipolar ingression into the segmen- 

 tation cavity and thus a solid morula is formed, having all cells similar each to each. The 

 peripheral layer of cells forms the ectoderm of the planula larva. Before the formation of the 

 ectoderm the cell boundaries become indistinct as in Turntopsis, but later they reestablish 

 themselves. 



Bougainvillia macloviana Lesson. 



Cyanea bougainvillii, LESSON, 1830, Voyage dc la Coquille, Zoo]., tome 2, part 2, 2d div., Zoophytes, p. 118, plate 14, figs. 3, 



D-D'". 



Bougainvillea macloritina, LESSON, 1843, Hist. Zooph. Acal., p. 290. AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 344. 

 Hippocrene macloviana, HAECKEL, 1879, Syst. der Medusen, p. 90, taf. 5, fign. I, 2. BROWNE, 1902, Annals and Mag. Nat. Hist., 



ser. 7, vol. 9, p. 278. BEDOT, 1905, Revue Suisse de Zool., tome 13, p. 135 (literature 1830-50). 



Adult medusa. Umbrella a little higher than broad, about 15 mm. high, with a quad- 

 rangular margin, and with longitudinal furrows on the exumbrella. There are 4 V-shaped, 

 radially situated tentacle-bulbs, each giving rise to about 35 to 65 tentacles arranged in a 

 double row. There is a single ocellus at the base of every tentacle. The stomach is small, cubi- 

 cal, and situated upon a broad, cone-shaped peduncle. 4 narrow, perradial lobes extend out- 

 ward from the stomach along the whole length of the peduncle. The mouth is small, with 4 

 short, perradial lips placed at a point about two-thirds down the depth of the umbrella-cavity. 

 There are 4 closely and thickly branched tentacles, each with 80 to 100 terminal branches 

 ending in knob-like clusters of nematocysts. The gonads are developed upon the interradial 

 sides of the stomach and extend over the sides of the perradial lobes of the stomach, hang- 

 ing down in a folded band from the peduncle. The stomach and tentacle-bulbs are yellow, 

 while the gonads and ocelli are brownish to black. This species is abundant at the Falkland 

 Islands. Mature specimens were recently obtained by Vallentin between November and 

 February at Stanley Harbor and described by Browne. Haeckel's specimens appear to 

 have been immature. 



Bougainvillia principis. 



Margelis principis, STEENSTRTP, 1850, Vidensk. Meddel. Nat. For. Kjobenhavn, p. 35. 



Bougainvillea fruticosa+ B. dllmani, ROMANES, 1876-77, Journal Linnean Soc. London, Zoo!., vols. 12, 13, pp. 526, 190. 

 Margelis principis, HAECKEL, 1879, Syst. der Medusen, p. 88, taf. 6, fign. 14-16. BROWNE, 1895, Proc. and Trans. Liverpool 

 Biol. Soc., vol. 9, p. 266. 



Bell nearly spherical, 6 to 7 mm. wide, 5.6 mm. high. Bell-walls only moderately thick 

 and quite uniform. 4 marginal clusters of tentacles. Each cluster arises from an epaulet- 

 shaped base, and contains 25 to 30 short tentacles, shorter than the bell-radius. There is an 

 ectodermal ocellus on the velar side of each tentacle near its base. The basal epaulets of the 

 tentacles are somewhat wider than the interradial parts of the margin between them. 



The stomach is short, swollen, and without a peduncle. It is not half as long as the depth 

 of the bell-cavity, and its interradial sides are occupied by 4 swollen gonads. The 4 oral 

 tentacles each branch dichotomously 4 to 5 times, thus giving 20 to 30 knob-shaped, terminal 

 branches in each quadrant. Color ( ?) 



Found off the eastern coast of Scotland and in the North Sea, at Far-Oer Island. 



The hydroid is unknown. 



This medusa is distinguished by its short stomach and the remarkable length of its mar- 

 ginal tentacle-epaulets, which are linear, not triangular, in outline. 



Bougainvillia fulva Agassiz and Mayer. 



Bougainvillea fulva, AGASSIZ, A., and MAYER, 1899, Bull. Mus. Comp. Zool. at Harvard College, vol. 32, p. 162, plate 2, fig. (>; 

 Ibid., 1902, Mem. Mus. Comp. Zool. at Harvard Coll., vol. z6, p. 145, plate 2, fig. 8. MAAS, 1905, Craspedoten 

 M-Musen der Sibog/i Exped., Monog. 10, p. 10, taf. I, fig. 8; taf. 2, fign. 9, 10: 1906, Revue Suisse de Zool., tomr 14, 

 p. Sy, plate 2, figs. 4, 5. BIGELOW, H. B., 1909, Mrm. Mus. Comp. Zool. at Harvard College, vol. 37, p. 195, plates 6 

 and 44. 



