322 



Z. ASCIDIOIDA. 



Plumatella. 



does not colour at all, if not a yellow, the granules of the perisperm 

 which their appearance suggested to be amylaceous, but alcohol sepa- 

 rates from them a fatty substance, for, in spontaneous evaporation, 

 this menstruum deposits on the object-glass a white layer over which 

 water glides without raising any thing from it. 



On examining by refraction one of the eggs with a magnifier of 

 100 diameters, very often another transparent narrow margin becomes 

 visible, which overlaps all the circumference and indicates an external 

 envelope of extraordinary delicacy. On one side of this there is to be 

 distinguished an evident trace of the old adhesion of the egg to the 

 walls of the tubes which enclosed them, — a point which may be call- 

 ed the hilum. Very often, however, this delicate tunic may be 

 sought for in vain on other eggs. 



43. Plumatella, * Bosc. 

 Character- Polypidom fixed, membranaceous, confervoid, 

 slender, tubular, irregularly branched ; the polypes issuing from 

 the apices of the branches. — Polypes ascidian, croicned with a 

 single series of ciliated tentacula. 



it- 

 1. P. REPENS, " stem adhering ; tentacula disposed in a cres- 

 cent." Rev. Dr Fleming. 



Fig. 51. 



Tubipora repens, Lin. Syst. edit. 10, 790 Tubularia repens, Mull. 



Verm. i. ii. 16. Zool. Dan. prod. 254. Bosc, Vers, iii. 93 Tub. 



reptans, Turt. Gmel. iv. 669. Plumatella repens, Lam. Anim. s. 



Vert. ii. 108. 2de edit. ii. 123. Flem. Brit. Anim. 322. Stark, Elem. 



ii,441 Naisa repens, Coral. 98 La Plumatella rampante,5Zamr. 



Actinolog. 490. f- 



* The diminitive oiplumata — plumed. 



f To this synonymy it may be useful to add the following, communicated to me 

 along with a dried specimen of the polypidom, by J. Hogg, Esq. " A small 

 piece of it is figured in Schaff. Armpolyp. tab. i. fig. 1, 2, published in 1754. 

 The next representation of it is in tab. 19, fig. 1-5, in the Bulletin Philomatique 



