216 



VELELLID.E. 



Family VELELLIDiE Esch. 



VelellidcB Esc-a. (reslr. Aqsss.). Syst. d. Acal., p. 165. 1829. 



Vclclla; Less. Zooph. Acal.. p. iJe'o. 1843. 



VdelUdce AciASS. Cout. Nat. llist. U. S., IV. p. 366. 1862. 



VELELLA L.VMK. 



Velella LxMK. Anim. s. Vert., 11. 1819. 



Velclla Less. Zooph. Acal., p. 562. 1843. 



Velella Ag.\ss. Cont. Xat. Hist. U. S., IV. p. 366. 1862. 



ruilaria Esch. Svst der Acal. p. 166. 1829. 



Chri/aomitra Gegexb. ; in Zeit. f. Wiss. Zool., p. 231. 1856. Medusa. 



Linuche Escn. Syst. der Acal., p. 91. 1829. Medusa. 



fRalaria Pagesst. ; in Zeit. f. Wiss. Zool., XII. p. 496. 1863. 



Velella mutica Bosc. 



Velella mutica Bosc. Hist. Nat. d. Vers, U. p. 158. 

 Velella mutica Less. Voyage de la Coquille, PI. 6. 1829. 

 Velella mutica Less. Zooph. Acal., p. 571. 1843. 

 Velella mutica Agass. Cont. Nat. Hist. U. S., IV. p. 366. 



1862. 



The free Medusa of Velella resembles so exactly that produced by 

 some of the Tubularians — Euphysa and Globiceps, for example — that 

 it would seem the most natural thing to place these Medusa3 among 

 Tubularians, as McCrady has done ; but the polymorphism of the 



Fig. 355. 



Fig. 356. 



HydrfG (Fig. 355) and the presence of the float (Fig. 35G) associate 

 the Hj'drurium with the Porpitaj. The free Medusa is but another 

 link showing how close is the relation between the floating and fixed 

 Hydro ids. The Medusa figured here (Fig. 357) is one which has just 

 freed itself The chymiferous tubes, as well as the proboscis, are of a 



Fig. 355. An enlarged view of one of the fertile Ilydrre of Velclla. a, base of attachment of 

 Hydra ; b, end of Hydra ; iJ, d, clusters of Medusae. All tliesc figures are copied from I'rofessor 

 Agassiz's Contributions, Vol. IH. 



Fig. 356. Velella, seen from below, to show the Hy<lr!B. m, opening, so-called mouth ; a, fer- 

 tile Hydra; situated between the mouth and the outer tentacles, the sterile Hydra". 



Fig. 357. Magnified view of a free Medusa of Velella mutica Bosc. o, proboscis ; h, chymif- 

 erous tube ; c, circular tube. 



