LEPTOMEDUSiE — CLYTIA, PHIALIDIUM. 



265 



The young of this medusa are found among the Bahama Islands during the winter. We 

 met with a great swarm of them near Anguilla Cay, Great Salt Bank, Bahamas, on February 

 25, 1893. McCrady, 1857, found a single specimen in Charleston Harbor, and Brooks, 1882, 

 found both the hydroid and medusa at Beaufort, North Carolina. 



Brooks identifies the hydroid stock with Campamdaria nohformis McCrady, 1857 

 (Gymn. Charleston Harbor, p. 92, plate II, fig. 4). Brooks, 1882, says the hydroid is very 

 much like Clytia (Platypyxis) cylindrica Agassiz, L., 1862 (Cont. Nat. Hist. U. S., vol. 4, pp. 

 306, 354, figs. 42-44, p. 307). Distal end of reproductive calycle is truncated squarely instead 

 of flaring, and the cross-section of the calycle is a circle instead of an ellipse, as in Clytia cylin- 

 drica. The calycle contains 4 or 5 medusae, which are nearly equal in size each to each, and they 

 are discharged in quick succession, the last escaping within a few minutes after the first. The 



tentacles and lithocystsof the youngmedusa 

 are similar to those of Epenthesis bicophora. 

 Mayer, 1901, studied the variations of 

 this medusa, which is of interest, owing to 

 the fact that a 5-rayed species, Pseudoclytia 

 pentata, is probably derived by discontin- 

 uous variation as a mutation, either from 

 C. folleata itself or some closely allied form. 

 C. folleata is quite constant, as is shown by 

 the following summary of the variations of 

 275 specimens found at Tortugas, Florida. 

 Of these 275 medusa?, 255 were radially symmetrical, and only 2 medusa; had both radial- 

 canals and lips irregular. 



Clytia universitatis Torrey. 



Clytia universitatis, Torrey, 1904, University of California Publications, Zool., vol. 2, p. 19, figs. 12, 13. 



Stem of hydroid more than 200 mm. long, irregularly branched, forming bushy tufts. 

 Stem and branches polysiphonic. Pedicels of hydranths long and almost completely ringed. 

 Hydrothecae deep, conical, with slightly bulging sides and with 12 to 15 triangular, sharp- 

 pointed, marginal teeth. Hydranths range in length from 0.7 to 0.83 mm. and in width from 

 0.37 to 0.42 mm. Hydranths have about 28 tentacles. 



Gonangia club-shaped and borne on stem, branches, or hydranth pedicels. They are 

 0.95 to 1 mm. long and 0.39 to 0.41 mm. wide. Pedicel very short and may exhibit a single 

 annulus. Outline of sides of gonangia somewhat wavy with one or two annulations near 

 broad distal end. Numerous medusa-buds, the oldest of which have 4 tentacles. 



San Diego Bay, coast of California. 



Clytia rangiroae. 

 Epenthesis rangirox, Agassiz, A., and Mayer, 1902, Mem. Mus. Comp. Zool. Harvard College, vol. 26, p. 145, plate I, fig. 4. 



Bell slightly flatter than a hemisphere, 7 mm. in diameter. Bell-walls thin and flexible. 

 16 well-developed tentacles with large, conical, basal bulbs. 16 lithocysts, each containing a 

 single, spherical concretion, alternate in position with the i6tentacles. Velumbroad. 4 straight, 

 slender radial-canals and a narrow circular vessel. Manubrium very short and quadratic in 

 cross-section, 4 slightly recurved lips. The 4 gonads are found upon the 4 radial-canals very 

 near the circular vessel. In the single specimen obtained each gonad contained 6 to 8 promi- 

 nent eggs. The medusa is transparent with the exception of the manubrium, gonads, and 

 tentacle-bulbs, which are translucent and milky in color. This form was found in the lagoon 

 of Rangiroa Island, Paumotus, South Pacific, on September 23, 1899. 



Genus PHIALIDIUM Leuckart, 1856. 



Oceania (in part), Peron et Lesueur, 1809, Annal. Mus. Hist. Nat. Paris, tome 14, p. 344. 



Oceania, Agassiz, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 352. — Agassiz, A., 1865, North American Acalephae, p. 70.— Agassiz 



and Mayer, 1899, Bull. Mus. Comp. Zool. at Harvard College, vol. 32, No. 9, p. 167. — Mayer, 1900, Bull. Mus. 



Comp. Zool. at Harvard College, p. vol. 37, 50. — Hargitt, 1904, Bull. U. S. Bureau of Fisheries, vol. 24, p. 49. 

 Diantta (in part), Lamarck, 1817, Hist. Anim. sans Vertebres, tome 2, p. 505. 

 Thaumantias (in part), Eschscholtz, 1829, Syst. der Acalephen, p. 79. 



