COMPOUND ASCIDIA. 169 



planted on the surface of the specimen. The orifices of many of the other 

 ascidiaj were rather indistinct. — Fig. 9. 



The whole product might have been compared to an irregularly 

 flattened cake. 



(6.) A yellowish-brown specimen was covered by about sixty systems, 

 arranged in whitish irregular ellipses, distributed over the whole surface. 

 Each system consisted of a large central dilateable cone, environed by flask- 

 shaped ascidiae, of which only the shoulder and larger orifice were visible. 

 This orifice exhibited four large spinous projections directed inwards, per- 

 liaps denoting four concave circular arcs, which might expand as a circle like 

 others. The central cavity was turgid, being evidently full of water, as 

 white specks were floating there during its distension. 



This specimen might have been circumscribed by an irregular qua- 

 drangle of two inches and a half; the whole like a very flexible, flattened 

 fig, under half an inch thick. — Plate XLL, fig. 5, Botryllus. — Plate XL. 

 fig. 10, system of nine ascidia 1 , and the central cone. 



The whole subject remained sufficiently vigorous for a day or two, and 

 then perished, from being invested by a thin transparent coating of mould. 



These brief notices, together with the figures, may prove of some as- 

 sistance to those who have opportunities of obtaining specimens of the 

 Botryllus, and of extending the subject. 



But many additional illustrations are requisite to constitute species 

 from what has been said, as appearances were not sufficiently uniform to 

 enable me to do so. The rarity of the product has obstructed the pro- 

 gress of that investigation of form and properties, which profitably eluci- 

 date the nature of such interesting works of the creation. 



The following general conclusions may be nevertheless deduced from 

 the preceding narrative, irregular and defective as it is, regarding the 

 Ascidia papilla, the Botryllus verrucosus, and kindred ; recollecting that 

 all these names are provisional, that they may not interfere with the 

 priority of observation. 



I. The Ascidia papilla is a single perfect animal. 



II. It is commonly solitary in the adult ; but also dwells in numerous 



VOL. II. Y 



