198 



HTDRACTINIDiE. 



Family HYDRACTINIDiE Agass. 



Hi/draciinidce Agass. Cont. Nat. Hist. U. S., IV. p. 339. 1862. 



HYDRACTINIA Van Beneden. 



Hijdractinia Van Bexeden ; in Bull. Acad. Bel., VIII. 1841. 

 Hydraclinia Agass. Cont. Nat. Hist. U. S., IV. p. 339. 1862. 

 Synliydra QuAT. ; in Ann. des Scien. Nat., XX. p. 230. 1843. 



Hydractinia polyclina Agass. 



Hydraclinia polyclina Agass. Cont. Nat. Hist. U. S., HI. PI. 16 ; IV. pp. 227-239, 339, Figs. 



33-35; PI. 26, Fig. 18. 1862. 

 Hydra squamata Fab. Fauna Grcinlandica. No. 338. 

 Alcyonium echinatum Gould. Rep. Inv. Mass., p. 351. 



Hydractinia echinata Leidy. Mar. Inv. New Jersey and Rhode Island, p. 3, PI. X. Fig. 35. 1855- 

 Hydraclinia echinata Stimps. Mar. Inv. Grand Manan, p. 11. 1853. 

 Hydractinia echinata McCr. Gyran. Charleston Harbor, p. 66. 

 Clava squamata MoRCH ; in Beskriv. af Grdnland, p. 96. 

 Hydractinia polyclina Pack.; in Can. Nat. & Geol. Dec. 1863. 



As such constant reference is made to Hydractinia in the comparison 

 of the free colonies of Nanomia to the fixed Hydroids, figures of male 



(Fig. 329) and female (Fig. 330) colonies of this species are here intro- 

 duced to facilitate the comparison. 



Point Judith (Leidy) ; Atlantic coast of North America (L. Agassiz). 



Cat. No. 55, Grand Manan, 1859, A. E. Verrill. 



Cat. No. 56, Grand Manan, October, 1857, J. E. Mills. 



Cat. No. 57, Chelsea Beach, L. Agassiz. 



Cat. No. 58, Swampscott, Mass., March, 1859, S. Tufts. 



Cat. No. 59, Nantucket Shoals, July, 1849, L. Agassiz. 



Cat. No. 403, Nahant, Mass., July, 1862, A. Agassiz. 



Museum Diagram, No. 25, after L. Agassiz. 



Fig. 829. Part of male community of Hydractinia. a, a, sterile individuals ; b, fertile indi- 

 vidual ; d, male Medusaj ; o, o, proboscis ; t, elongated tentacle of sterile individuals. 



Fig. 330. Part of female community, a, sterile individual ; 6, fertile individual, producing 

 female Medusae, d, e,f, g, h, i ; o, peduncle of mouth ; c, individual with globular tentacles. 



