POLYPI, 539 



the form of bud-like bodies, including] the Hydraidse and 

 Tubulariadne. (2) [Those which have the ovaries formed 

 out of the transformed branches or piiinre, as the] Sertula- 

 riadte. (3) [Those which have the ovaries included in the 

 substance of the polypidom, as the] Asteroida ; and (4) [those 

 which have the ovaries forming a part of the internal con- 

 stitution of the individual Polypes, as the] Zoophyta Heli- 

 anthoida. But besides this, Forbes would separate the 

 Bryozoa [Ascidioida] from the Polypes, and place them, 

 near the compound Tunicata, among the Mollusca. 



Savigny's position, that a compound Ascidian is distin- 

 guished by its six tentacles from Alcyonium, whose polypes 

 always have eight, has been controverted by Milne Edwards 

 (Comptes rendus, t. xix, 1844, p. 1140), who has discovered 

 in the Mediterranean a true compound Ascidian, with eight 

 tentacles. 



M 'Andrew (Report of British Association, 1844, Notices, 

 p. G4, and Ann. Nat. Hist, xiv, 1814, p. 413) has dredged on 

 the West Coast of Scotland, and at a depth of twenty 

 fathoms, a Virgularia, two feet six inches long, with a 

 quadrangular stalk, which Forbes announced as new, under 

 the name of Tunicularia quadrangularis, but which he after- 

 wards convinced himself was no other than the " Pennatula 

 quadrangularis," Pall., from which Cuvier had formed the 

 genus Pavonia. 



A Zoophyte allied to Virgularia was observed by Darwin 

 (Voyage of Beagle, 1844, P. i, p. 116) in South America, 

 its slender, straight, and fleshy stalk, which was beset on the 

 sides with alternate polype-tubes, contained an elastic calca- 

 reous axis, and terminated, whilst it was blunted on the one 

 end, in a vermiform appendage on the other, which was 

 parted into two divisions, and contained minute, round, 

 yellow ova. At low water Darwin saw these Zoophytes 

 standing, like stubble, on the muddy sand, into which, how- 

 ever, when toiiched they withdrew themselves entirely. 



Three new polypidoms have been described by Hassall 

 (Ann. Nat. Hist, xi, 1813, p. Ill) under the names of 



