NARCOMEDUS^E — .EGINOPSIS, CUNINA. 473 



Bell hemispherical or higher, 15 to 25 mm. wide. 8 peronial strands 45 apart, 4 tentacles 

 90 apart, project from the sides of the bell in the radii of 4 alternate, peronial strands. These 

 tentacles are 1 to 2 times as long as the bell-diameter. There are 16 terminal, peripheral 

 stomach-pouches on which gonads are developed. There is apparently no ring-canal ( ?) 

 The mouth is a simple, round opening at the center of the lenticular stomach. The bell-margin 

 displays 4 deep clefts in the radii of the tentacles and 4 shallow clefts 90 apart from these. 

 The medusa is translucent bluish or faint red. Sensory-clubs ( ?) (See fig. 309a.) 



This species appears to be fairly common in the Arctic Ocean. It ranges from Japan 

 northward in the Pacific, and from the southern coast of New England northward in the 

 Atlantic. 



It is a difficult medusa to preserve and our knowledge of it is still very imperfect. In com- 

 mon with many other Narcomedusx the extreme transparency of the bell renders it difficult 

 to distinguish the shape of the stomach-pouches in living specimens. 



.fljginopsis (?) pachyderma. 



Campanula pachyderma, Agassiz, A., 1865, North Amer. Acal., p. 52, figs. 70-75.— Maas, 1905, Craspedoten Medusen der 



Siboga Expedition, Monog, 10, p. 70. 

 Aigina (&ginaria) pachyderma, Haeckel, 1879, Syst. der Medusen, pp. 339, 340. 

 .Egina pachyderma, Maas, 1905, Craspedoten Medusen der Siboga Expedition, Monog. 10, p. 70. 



The bell is about 1.5 mm. in diameter and is flatter than a hemisphere, the sides being 

 somewhat flaring. There are 4 radially situated, stiff tentacles, each being about 1.5 times as 

 long as the bell-diameter. These tentacles are covered with clusters of nematocyst-cells. Each 

 tentacle is said to be provided with a large basal bulb, the upper side of the ectoderm of which 

 contains a number of brown-colored pigment-granules, while in the lower portion there 

 is a dark-brown pigment-spot. The tentacles are said to be hollow and their bases are 

 put into communication each with each by means of the circular vessel ( ?) There are said 

 to be 8 simple "radial tubes." 4 of these lead to the 4 tentacles and the 4 others are 

 situated 45 away from the latter. The velum is very large and hangs downward below the 

 level of the tentacles. It consists of 8 loops corresponding to the 8 "radial tubes." The manu- 

 brium is conical and is about as long as the bell-height. It is capable of much contraction and 

 expansion. The mouth is a simple, round opening. The gonads occupy 8 horseshoe-shaped 

 pouches of the gastrovascular cavity situated midway between the 8 "radial tubes." The bell 

 is of an ocher-yellow color and there are a number of dark-brown nematocyst-bearing spots 

 scattered over its outer surface. Marginal sense-clubs ( ?) 



The above description, taken from that of A. Agassiz, 1865, has been supplemented by a 

 study of his original figures. It is reproduced in the hope that the medusa may in the future be 

 recognized. In his assiduous studies of the medusae of the New England coast, Dr. Agassiz 

 discovered a number of species which have not been taken since. Moreover, in the days when 

 he made the studies for his "North American Acalephae" the water was pure in many harbors 

 now polluted and the medusa-fauna has greatly changed in consequence. Therefore, although 

 this extraordinary medusa has not been seen since its discovery in 1862 at Nahant, Massa- 

 chusetts, in July and September, we can not discard it merely because recent explorations 

 have failed to reveal it. 



If Dr. Agassiz's account be accurate, this medusa exhibits certain extraordinary features 

 the combination of which is not seen in any known Narcomedusa. For example, it is stated to 

 have prominent clusters of nematocysts upon its hollow tentacles, and to have basal ocelli. 

 The 8 "radial tubes" may be peronial strands ( ?) This being the case, the medusa might be 

 a young Mginopsis, but it is possible that the 4 interradial "canals" are merely appearances 

 due to contraction and the medusa may be a young Mgina. 



Genus CUNINA Eschscholtz, 1829. 



Cunina, Eschscholtz, 1829, Syst. der Acalephen, p. 1 16.— Schulze, 1875, Mitt. Naturw. Verein Steiermark, p. 125 (develop- 

 ment). — Metschnikoff, 1886, Embryol. Studien an Medusen, Wien, pp. 23, 102 (development). — Maas, 1893, Ergeb. 

 der Plankton Expedition, Bd. 2, K. c, p. 51 ; 1904. Resultats Camp. Sci. Albert 1" Prince de Monaco, fasc. 28, p. 31.— 

 Woltfreck, 1905, Verhandl.Deutsch.Zool. Gesell., 15 Jahresvers., p. 117 (development).— Stschf.lkanowzeff, 1906, 

 Mitth. Zool. Sta. Neapel, Bd. 17, p. 433.— Bigelow, H. B., 1909, Mem. Mus. Zool.at Harvard College, vol. 37, p. 55. 



Cunina, Haeckel, 1879, Syst. der Medusen, pp. 318. 



