Chap. IX. 



TABULAR VIEW. 



339 



Syncoryna Ehr. (restricted).^ — Corclylomorpha Allin. 

 S. parasitica Ehrenb. — Mediterranean (Cavolini). 

 S. lacustris Ag. — Cordylomorpha lacustris AUm., Phil. Trans. R. S., 

 1853, PI. 25, fig. 1. — Duhlin, Ireland (Allman). — Professor 

 Leidy has discovered another species in Newport Harbor, R. I. 

 2nd Family. Hydractlmd.^ Ag? 



Hydractinia VanBened. See p. 227. 



H. echinata Johnst. — Hydr. rosea and H. lactea VanBen. — Scotland 

 (Fleming); British Coast (Johnston); German Ocean (VanBen.). 

 H. polyclina Ag. — North America, Atlantic coast (Agassiz). 

 3d Family. Sarsiad.e Forbes (restricted).^ See pp. 184 and 217. 



Coryne Gdrt. — Hydra: Coryne Gdrt., Syncoryne Ehr., Stij^nla Sars, 

 Hermia Johnst. — Medusa : Sarsia Less., Sthenyo Dig'ar.* 



but in the former the tentacles are simple, and 

 only sessile medusis-buds are produced, while the 

 latter produce free medusje, and have knobbed ten- 

 tacles. In Cladoneniidaj the clavate tentacles are 

 arranged in worls and cross-wise. In Hydractinida; 

 there are two kinds of Hydra?, each kind with 

 diflFerent tentacles. In Bougainvillida; and Euden- 

 droida? the tentacles encircle a well-defined crown, 

 and the apex of the Hydra assumes, in the latter, 

 the form of a distinct proboscis. In Tubularida; 

 proper the proboscis has tentacles also, but of the 

 same kind as the crown, while in Pennaridaj the 

 coronal tentacles are simple, and those of the pro- 

 boscis clavate. In Nemopsida; the Hydroid com- 

 munity is free and locomotive, and in Nucleiferte 

 the medusae-buds arise from a creeping stolon, and 

 not from the pedicel, nor from the head of the 

 Hydra, as in the other families. 

 ^ Syncoryna, Ehrenberg, Corallenthiere, Vert. Akad. 

 Wiss., Berlin, 1834, p. 70. " Hue 

 Sertulariain purasiticam Cavolini re- 

 ferrem : Syncoryna parasitica." The 

 three other species belong to the 

 genus Coryne Gaert. 

 Cordylopliora, Allman, Proc. Brit. Assoc, 1843. 



" Allman, Annals and Mag. Nat. Hist., 



May, 1844, XIII., p. 328. 

 " Allman, Philos. Trans. Roy. Soc, 



1853, p. 367. 



Gorydendrium, VanBeneden, Bullet. Acad. Roy., 

 Bruxelles, p. 313, Nov. 1844. 

 " Dana, Zoophytes, 1846. 



" Dana, Synopsis Zooph., 1859, p. 148. 



Sertularia (parasitica), Cavolini Mem. Polypi Ma- 

 rini, 1785, PI. VI. Figs. 8-13, and 

 Sprengel's transl., 1813, p. 83. 



'^ This family is very peculiar and distinct from 

 all other Tubularians. The communities consist 

 of two kinds of Hydrae, equally developed, the 

 ones sterile with simple tentacles, the others fertile 

 with knobbed tentacles. Medusse sessile, the males 

 and the females budding from different colonies. 

 McCrady is mistaken in stating that the medusae- 

 bearing Hydraj are not tentaculated. 



^ Forbes refers, also, the genera Bougainvillia, 

 Lizzia, Modeeria, Euphysa, and Steenstrujiia, to 

 this type ; but they belong to different families. As 

 here restricted, the Sarsiadie embrace only those 

 Acalephs the hydr;c of which are Coryne-like, and 

 the medusa? deep bell-shaped, with four long tenta- 

 cles in the prolongation of the four chymiferous tubes, 

 and a long simple proboscis, u[)on which the eggs 

 are developed. 



* It is to be hoped that henceforth zoologists 

 will refrain from giving names to Hydroids, the 

 development of which they have not traced, since 

 this genus shows to what complication of the nomen- 

 clature the prevalent practice has led. A true 



