I.-, I 



MF.m'S.E OF THE WORLD. 



Fir.. 8}.--/, \mnorea offlliita, after Agassiz and 

 Mayer, in Mem. Museum Comp. 

 Zool. at Harvard College. 



and each contains a mass of red entodermal pigment. In addition to this there is a prominent 

 ectodermal ocellus upon the velar side of each tentacle at a short distance outward from the 

 basal bulb. The velum is narrow. There are 4 straight, narrow radial-canals and a slender cir- 

 cular vessel. The peduncle of the manubrium is wide and quadratic in cross-section and its 

 lower portion near the stomach consists of highly vacuolated, entodermal cells. The stomach is 

 pear-shaped and the mouth is a simple, round opening. The entire manubrium extends about 



half the distance from the inner apex of the bell-cavity 

 to the level of the velar opening. There are 4 well- 

 developed, radially placed, oral tentacles, each one of 

 which is about half as long as the height of the manu- 

 brium. Each oral tentacle branches dichotomously 4 

 times, thus giving rise to 16 distal knobs. Each knob is 

 thicklycovered with a bristling cluster of fusiform nema- 

 tocyst-cells. In addition to these there are several 

 patches of nematocystic bristles upon the sides of the 

 main shaft of each oral tentacle. The gonads are devel- 

 oped in 4 interradial regions on the walls of the stomach. 

 The entoderm of the tentacle-bulbs and of the stomach 

 is brick-red. The ectodermal ocelli are black. A num- 

 ber of these medusae were obtained on the surface in 

 the lagoon of Makemo Island, Paumotus, South Pacific, on October 23, 1899. 



This species may be identical with Lymnorea triedra Peron et Lesueur = L. probosciJea 

 Haeckel, but the published drawing of this medusa is evidently inaccurate and the description 

 so brief and vague that it will probably never be possible to redetermine the species. /,. trn'Jrn 

 is described from Bass Strait, between Australia and Tasmania. 



Lymnorea borealis Mayer. 

 Plate 15, figs. I to 3. 



Lvmnorea borealis, MAYER, 1900, Bull. Mus. Comp. Zool. at Harvard College, vol. 37, p. (>, figs. 16-18, plate 5. 



( ;} Limnorea tioivegica, BROCH, 1905, Bergens Museums Aarbog, No. 11, p. 5. 



(?) Cvttftinda nreolala, BROWNF., 1897, Proc. Zool. Soc. London, p. 817, plate 48, figs. I, 2. (Podocorvtif!') 



Bell 3 mm. high. It is higher than a hemisphere and is acorn-shaped, with a low, blunt 

 apical projection. The bell-walls are thin. There are 32 marginal tentacles, each about halt 

 as long as the bell-height. They are quite stiffand are carried curled upward, above the margin. 

 Their basal bulbs are large and densely pigmented. The velum is well developed. There are 

 4 straight, narrow radial-canals and a slender, simple, circular vessel. The manubrium is 

 slender and pyriform and mounted upon a very short, solid peduncle. It is cruciform in cross- 

 section. The mouth is flanked on its 4 radial corners by 4 short dichotomously branching oral 

 tentacles (plate 15, fig. 2). Each oral tentacle branches dichotomously twice, thus giving 4 

 tentacle tips in each quadrant. These tentacle tips are knob-like and armed with long spindle- 

 shaped nematocysts (plate 15, fig. 3) very much as are the oral tentacles of Lymnorea ocellata. 

 The 4 gonads are found in four longitudinal, interradial, swollen regions in the ectoderm of the 

 stomach-wall. The immature eggs are transparent and give a reticulate appearance to the 

 surface of each gonad. The entoderm of the manubrium and tentacle-bulbs is bright-red. 

 There are no ocelli. 



Three specimens were taken on the surface at Eastport, Maine, on September 19, 1898. 



Broch, 1905, gives a brief description of a Lymnorea from the coast of Norway which may 

 be identical with this species. He states that there is a pair of very short, oral tentacles at each 

 of the 4 corners of the mouth and that each of these forks dichotomously twice, thus giving 8 

 terminal knobs at each radial corner of the mouth. There are 16 to 22 tentacles. In other 

 respects his description accords with that of/,, borealis, allowance being made for contraction 

 due to preservation in Broch's specimen. He gives no figures and does not mention the color. 



Lymnorea alexandri Mayer. 

 Plate 15, figs. 4 to 9. 



Lvmnorea ale\andri, MAVF.R, 1906, Mem. Nat. Scj. Museum Brooklyn Institute, vol. i, p. 10, plate I, figs. 1-5*7. 

 M.ir.i.lm, i/)., BROOKS an. I KITTKNHOHSF., 1907, Proc. Boston Soc. Nat. Hist., vol. 33, p. 435, plate 31, fig. 8. 



