AXTHI i.MKDTS.E SARSIA. 57 



Sarsia mirabilis var. reticulata. 

 Plate 4, figs. 3 and 4; plate 5, fig. 6. 



Syndictyon reticulatum, A. AGASSIZ in L. AGASSIZ'S, 1862, Cont. Nat. Hist. U. S., vol. 4, p. 340. AGASSIZ, A., 1865, North Amer. 



Acal., p. 177, figs. 290-300. 



Syncor\ne reticulata, ALLMAN, 1871, Monog. Tubul. Hydroids, p. 283. 

 Syndictvon reticulatum, HAECKF.L, 1879, Syst. der Medusen, p. 21. 



( ?) Syndictyon raiculalum, MAAS, 1893, Ergeb. der Plankton-Expedition, Bd. 2, K. c., p. 67. 

 (tySarsia turrreula, MrCRADV, 1857, Gymn. Charleston Harbor, p. 36, plate 8, figs. 6-8. 

 S\ncor\ne reticulata, HARGITT, 1904, Bulletin Bureau of Fisheries U. S., vol. 24, p. 30. 

 Sarsia reliculata, HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 45, figs. 41-43. 

 (?) Sarsia pulchella, AI.I.MAN, 1871, see Hartlaub, 1907, Nordisches Plankton, Nr. 12, p. 34, fig. 27 (abnormal twin medusa:, 



fig. on p. 109). SPAGNOLINI, 1876, Catalogo Acalefi Mediterranco, p. 18, tav. 2, figs. i. 2. 



Adult medusa. Bell ellipsoidal in shape, being about 4 mm. in height and 3.5 mm. in 

 diameter. No apical projection. Gelatinous substance quite thick at the aboral pole, but 

 thin at the bell-margin. There are 4 long, highly contractile tentacles, I at the base of each 

 radial-canal. Surfaces of these tentacles covered with prominent nematocyst capsules. Basal 

 bulbs of tentacles well developed and each one contains an ectodermal ocellus upon its outer 

 side. Velum wide and thin. There are 4 straight, narrow radial-canals, and a slender circular 

 vessel. Manubrium short and club-shaped, and does not extend far beyond the velar opening. 

 Mouth a simple, round opening. Genital products developed along the greater part of the 

 length of the manubrium. The entoderm of the manubrium and tentacle-bulbs is brick-red. 



Hydroid and young medusa. Smaller than Coryne mirnliilis, being not more than 3 mm. 

 in height. Stems slender and hardly ever branch, excepting in old specimens, which some- 

 times give rise to a single branch near the base of the stem. Polypites large and club-shaped, 

 and having several whorls composed of 8 to 10 short tentacles. The medusae develop 

 among the tentacles near the proximal base of the polypite. When set free the young medusa 

 is remarkably large, being about 1.5 mm. in diameter. The bell is covered \\irh reticulated 

 clusters of nematocyst-cells (plate 4, figs. 3, 4) which are especially numerous near the bell- 

 margin above the circular canal. Some of these nematocyst-cells are large and round, while 

 others are narrow and long. The tentacles are thickly covered with helically arranged clusters 

 of nematocyst-cells. These cells (plate 4, fig. 4) are ellipsoidal in shape and are mounted 

 upon a short basal pedicel. Each cell gives rise to a long, sharp-pointed, sensitive hair. The 

 nematocyst thread lies coiled in a helix within the cavity of the cell. As the medusa becomes 

 mature the reticulated nematocysts disappear from the surface of the exumbrella and the 

 nematocysts upon the tentacles become less prominent. This medusa is found upon the Ne\\ 

 England coast from April until June. It is distinguished from Sm-sm mirabilis only by its 

 nematocyst-covered tentacles and exumbrella and its small hydroid. It appears also to be 

 constantly brick-red, while 5. mirabilis is highly variable in color. It is often impossible 

 to distinguish mature medusae of S. reticulata from those of .V. mirabilis. It is possible that 

 the S. pulchella of Spagnolini, 1876, from Naples, Italy, is identical with .S'. r, n, uLita. 



Sarsia eximia Boehm. 



Coryne eximia, ALLMAN, 1859, Annals and Mag. Nat. Hist., ser. 3, vol. 4, p. 141; 1864, Ibid., vol. 13, p. 357. 



Syncoryne eximia, HINCKS, 1868, Hist. British Hydroid Zooph., p. co, plate 9, fig. 2. ALLMAN, 1871, Monog. Tubul. Hydroids, 



p. 282, plate 5. 

 Sarsia eximia, BOEHM, 1878, Jena. Zeitschrift fur Naturw., Bd. 12, p. 191, taf. 6, figs. 7-26; taf. 7, figs. 1-6. (In part), HAEC- 



KEL, 1879, Syst. der Mcdusen, p. 17. HARTLAI P II, 1894, \Vissen. Meercsuntcrsuch. Komini^. Mo-rc. Kid, lldi;ii]and, 



Ser. 2, Bd. i, p. 187. 



Svncorvne eximia (hvdroid). NUTTINC;, 1901, Proc. Washington Acail. Sa., vol. 3, p. 166, plate 14, figs. 3, 4. 

 Sarsia eximia, BROWNE, 1905, Proc. Roy. Soc. Edinburgh, vol. 21;, p. 756 (hydroid and medusa). BROCB, 1905, Bergcns 



Museums Aarbog, No. 11, p. 4. 



Sarsia tximia=S. bretonica, HARTLAUB, 1907, Nordisches Plankton, Nr. 12, p. 8, figs, i, 2a, 26 (full list of recent literature). 

 Syncorync eximia, BROWNE, 1907, Journal Marine Biol. Association, vol. 8, p. 37 (growth of the hydroid). 



This form is found off the coasts of Great Britain, Helgoland, Shetland Islands, Norway, 

 and Juneau, Alaska (Nutting). For details of the medusa, see tabular description of the 

 medusas of Sarsia. 



The hydroid is about 30 mm. high, forming a bush-like cluster of profusely branched 

 stems; the branches are short and simple and arise very irregularly from the main stems, 

 and are usually faintly ringed at their points of origin. The main stem is usually unringed, 



