BOTRYLLUS. 21 



Very common on stones and sea-weeds near low water-mark, 

 all round the British Islands.* 



2. B. poLYCYCLus, Savigny. 



" Botryllus stellatus, Renieri, Le Sueur, and Desmarest." — Polycyclus, Lamarck, 

 Mem. du Mus. t. i. p. 340. — Botryllus polycyclus, Savigny, M6m. pt. 2, p. 

 202, pi. 4, fig. 5, and pi. 21. 



A gelatinous, translucent, grey crust, with reddish and purple 

 marginal tubes. Systems numerous, of from eight to twenty or 

 more individuals. Oval ; bluish or purple. Orifices bordered by 

 purple; the branchial aperture surrounded by eight large white 

 or bluish spots, divided by deep purple spaces : radial line simi- 

 larly coloured. Mass grows to several inches. Individuals one- 

 twelfth of an inch or less. 



" Much more common in the north of Ireland than B. Schlos- 

 seri : chiefly on the leaves of Laminaria digitata," W. Thomp- 



" ' Many of these bodies I have found so thick and large as to resemble the great 

 branched madrepora coral, especially as they are generally to be met with cover- 

 ing and enclosing the stem and branches of this stiff, ramose fucus.' Thus far Dr. 

 Schlosser. 



" ' I have had an opportunity lately of examining this curious, fleshy, coral-like 

 figure in the microscope, and find that all the interstices between the stars are 

 filled with eggs of different sizes, each adhering by one end to a very fine capil- 

 lary filament. The smallest eggs are globular, and as they advance in size, change 

 to an oval figure ; from thence they assume the shape of one of the radii of the 

 stars. 



" In several of these stars I have observed a smaller radius, as it were, endea- 

 vouring to get into the circle ; and notwithstanding their seeming connexion in 

 the centre as one animal, I believe I shall soon be able to shew you, in a drawing 

 from the microscope, that each radius is a distinct animal by itself. 



" I am, dear Sir, 



" Your most affectionate friend, 



"John Ellis." 



* Botryllus conglomeratus, Gaertner. 

 Gaertner in Pallas, Spic. Zool. fasc. 10, p. 39, t. 4, f. 6, a. A. — Alcyonium con- 



glomeratum, Gmelin. — Botryllus conglomeratus, Lamarck ; Savigny, Mem. pt. 



2, p. 204 ; Fleming, Brit. An. 470. 



" B. dactylis conglomeratis osculis edentulis terminalibus ; corpus gelatinosum, 

 molle, convexum ; plantis marinis adnatum." The true nature of this Ascidian, if 

 it be one, is very doubtful. It was taken by Gaertner on the Cornish coast. The 

 "Alcyonium Borlasii" and "A. constellatum" arc supposed species of Botryllus, 

 instituted by Dr. Turton from the rude figures of Borlase. 



