198 



HYDE ACTINIAE. 



Family HYDRACTINIDCE Agass. 



Hydractinidce AGASS. Cont. Nat. Hist. U. S., IV. p. 339. 1862. 



HYDRACTINIA VAN BENEDEN. 



Hydractinia VAN BEXEDEN ; in Bull. Acad. Bel., VIII. 1841. 

 Hydractinia AGASS. Cont. Nat. Hist. U. S., IV. p. 339. 1862. 

 Synhydra QUAT. ; in Ann. des Scien. Nat., XX. p. 230. 1843. 



Hydractinia polyclina AGASS. 



Hydractinia polyclina AGASS. Cont. Nat. Hist. U. S., HI. PL 16 ; IV. pp. 227-239, 339, Figs. 



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



Hydra squamata FAB. Fauna Grb'nlandica. No. 338. 

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



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

 Hydractinia echinata STIMPS. Mar. Inv. Grand Manan, p. 11. 1853. 

 Hydractinia echinata McCn. Gymn. Charleston Harbor, p. 66. 

 Clava squamata MORCH ; in Beskriv. af Grbnland, 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. 330. 



(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. 329. Part of male community of Hydractinia. , a, sterile individuals ; &, fertile indi- 

 vidual ; f/, male Medusa? ; o, o, proboscis ; /, elongated tentacle of sterile individuals. 



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

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



