72 



MEDUSAE OF THE WORLD. 



Corynitis agassizii McCrady. 

 Plate 5, fig. z. 



Corynitis agassizii, McCRADY, 1857, Gymn. Charleston Harbor, p. 30, plate 9, figs. 3-8. AGASSIZ, L., i86z, Cont. Nat. Hist. 



U. S., vol. 4, p. 340. AGASSIZ, A., 1865, North Amer. Acal., p. 183. ALLMAN, 1871, Monog. Tubul. Hydroids, p. 287. 

 Corynetts agassizii, HAECKEL, 1879, Syst. der Medusen, p. 49. 



( ?) Corvnetcs agassizii, MAAS, 1893, Ergcb. der Plankton Exped., Bd. 2, K. c., p. 67. 



Non Halocharis spiralis (hydroid), AGASSIZ, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 239, plate 20, figs. io-ioc. 

 Coryne agassizii (hydroid), McCRADY, 1857, Gymn. Charleston Harbor, pp. 29, 32. 



Non Corvnitis agassizii, HARGITT, 1904, Bull. U. S. Bureau of Fisheries, vol. 24, p. 42 (this is Gemmaria=ZancIfa). 

 Non Corynitis agassizii, NUTTING, 1901, Bull. I'. S. Fish Commission for 1899, vol. 19, p. 372, fig. 79 (this is Gcmmaria= 



Zanclca*). 



Non Corynitis agassizii, MURBACH, 1899, Quart. Journ. Microscop. Sci., New Ser., vol. 42, p. 354 (this is Gemmaria=Zanclea). 

 Syncoryne linvillei (hydroid), HARGITT, 1904, Biological Bulletin Woods Hole, vol. 7, p. 251, I fig; 1908, Ibid., p. 101, fig. i. 



Adult medusa. Bell miter-shaped and about 2.5 mm. in height. 8 longitudinal rows 

 of irregularly scattered nematocyst-cells are found upon the sides of the exumbrella immedi- 

 ately above the circular canal. 4 of these are situated above the tentacles and 4 are inter- 

 radial in position. The radially situated rows of nematocysts are longer than the interradial. 

 There are 4 straight, stiff tentacles, which are about three-quarters as long as the bell-diameter. 

 Each tentacle terminates in a large, knob-shaped swelling, the outer surface of which is thickly 

 covered with nematocysts. The entodermal core of this swelling is hollow and its lumen 



is placed in communication with the gastrovascular system 

 of the medusa by means of a slender entodermal canal 

 which extends through the entire length of the tentacle. 

 Wart-like clusters of nematocysts are scattered over the 

 shaft of each tentacle. The basal bulbs are large and 

 hollow, and each one contains a single ectodermal ocellus 

 upon the outer side. Velum well-developed. There are 4 

 straight radial-canals and a narrow circular tube. The 

 large conical apex of the bell is hollow and in direct com- 

 munication with the stomach of the medusa. The manu- 

 brium is very large and swollen and fills the greater part of 

 the bell-cavity. It extends almost to the level of the velar 

 opening. The mouth is situated at the extremity of a short 

 oesophagus. It is without prominent lips. The gonads 

 occupy the greatly swollen sides of the stomach, and their 

 outer surfaces are smooth. 4 deep, interradial furrows 

 extend down the sides of the stomach, so that the manu- 

 bnum is cruciform in cross-section. The entoderm of the 

 FIG. 35. Hydroid of Corynitis, after Hargitt, basal bulbs of the tentacles is strawberry-red and that 



iqo8, Biological Bulletin. ri 'iiiri I n 



of the terminal knobs of the tentacles is orange-yellow 



flecked with red-colored pigment-granules. The manubrium is dull yellow streaked with 

 strawberry-red and the entoderm of the radial-canals is faint yellow. The ocelli are dark- 

 brown or orange. 



The hydroid is a Syncoryne, and is described by Hargitt. It grows in tufts which are 

 sparingly branched and 15 to 30 mm. high. The hydranths are vasiform with cone-shaped 

 proboscis. There are 15 to 30 tentacles distributed over the proximal third of the body of 

 the hydranth. These tentacles terminate each in a knob-like free end. The pensarc is plain 

 or with only a slight annulation. The hydrorhiza is reticulated in a loose network. The 

 medusa-buds are borne upon the body of the hydranth, usually in small clusters at the bases of 

 the tentacles, each cluster supported upon a single peduncle, the terminal specimen always 

 maturing first. The medusae, while still attached to the hydroid, have 2 well-developed, dia- 

 metrically opposed, club-shaped tentacles and 2 small tentacle-buds. There are no ocelli. 

 There are 4 radial-canals and the umbrella is bell-shaped. In formalin the hydroid is pale- 

 yellowish, hydranth somewhat brownish, and gonophores reddish-brown or pink. This 

 hydroid was found by Dr. Henry R. Linville growing upon rocks and piles under "Mill- 

 dam Bridge "west of Shelter Island, Long Island Sound, New York. It is described by 

 Hargitt from preserved material under the name Syncoryne linvillei. When set free the 

 medusae have only 2 tentacles and 2 small, basal bulbs. 





