130 ANNELIDES. 



Others haA'e no membranous disk anteriorly; their two pectiniform 

 branchiae are equal and spiral*. 



There are sometimes two ranges of filaments on each comb f . 



In others again, only one of the two combs is thus formed ; the 

 other, which is smaller, enveloping the base of the first, — Sabella 

 unispira, Cuv. ; Spirographis Spallanzami, Yiviani, Phosph. Mar., pi. 

 iv, vj. 



There are some Avhose branchiae merely form a simple funnel 

 round the mouth ; their filaments, however, are numerous, crowded, 

 and strongly ciliated on the internal surface §. Their silky feet are 

 almost imperceptible. 



Finally, others have been described which have but six filaments, 

 arranged in a stellate form ||. 



Terebella, Cuv:%\ 



The Terebellae, like most of the Sabellae, inhabit an artificial tube, 

 but it is composed of grains of sand, and fragments of shells ; their 

 body, moreover, has fewer rings, and their head is otherwise deco- 

 rated. Numerous filiform and extremely extensible tentacula sur- 

 roimd their mouth; their branchii^, placed on the neck, are notinfun- 

 dibuliform, but resemble arbusculae. 



Several species are found on the coast of France, long con- 

 founded under the name of Terehella conchilega, Gm., Pall., 

 Miscel., IX, 14 — 22, m.ost of which are remarkable for tubes 

 formed of large fragments of shells, the edges of their opening 

 being prolonged into several little branches, composed of simi- 

 lar materials, and containing the tentacula. 



In the greater number there are three pairs of branchiae, which, 

 in those where the tube is branched, issue through a peculiar hole 

 formed for that purpose**. 



* The simple Sabell^e of Savigny, AmphUrite reniformis, Miill., Ver., XVI, 

 or Tuhularia penicillus, Id., Zool., Ixxxix, 1, 2, or Terebella reni/ormis, Gm. ; — 

 Ainph. infumUbulum, Montag., Lin. Trans., IX, viii ; — Amph. vesiailcsa, Id. lb., 

 XI, V. 



-f The Sabell-i Astart.e, Savig., such as the Sabella grandis, Cuv., or Indica, 

 Sav. ; — Tubularia magnijica, Shaw, Lin. Trans., V, ix. 



+ Tlie Sabell.e Spirographic.e, Sa^^gny. 



N.B. On account of the imperfection of the figure of Ellis, Coral., pi. xxxiii, I do 

 not know to which of these subdivisions we should refer the Amphitrite veniilabntm , 

 Gm. or Sabella penicillt'S, L., Ed. XII. 



§ Sub. villosa, Cuv., a new species. 



II Tubularia Fubriciu, Gm., Fabr., Faun. Groenl., p. 450 — the genus Fadricia, 

 Blainv. 



^ Linnreus, in his twelfth edition, had thus named an animal described by 

 Kcehler, and which might have belonged to this genus because it was thought to 

 perforate stones. Lamarck has employed the same name — An. sans vert., p. 324, 

 for a A'o'ewand for a Spio. The Terebella', Gm., comprehend Amphinoma, Nereides, 

 Serpulee, &c. Messrs. Savigny, Montag., Lamarck, and Blainville, employ this 

 name as above, which was proposed by me, Diet, des Sc. Nat., II, p. 79. 



** They are the simple Terebella of Savigny ; such as, Tereb. medusa, Sav., Eg., 

 Annel., T,f. 3; — Ter, cirrhuta, Gm., Miill., Ver., XV; — Ter. gigantea, Montag., 



