ASCIDIA. 



141 



1841, wherein that author refers to his previous observations in 1828. Not 

 having seen the latter, I am precluded from availing myself of them. A 

 few other more brief and incidental observations have appeared from very 

 intelligent authors. 



Here I propose merely to enumerate a few of our native species of 

 simple Ascidire, and that, as before said, as a prelude to further comment on 

 some singular points in the history of others, and especially of those con- 

 sisting of a multitude of individuals united indissolubly in compound 

 masses. 



§ 1. Ascidia villosa. — The Woolly Ascidia. — Plate XXXIV. Fig. 1. 

 — Unlike the common nature of all the Scotish Ascidia 3 , excepting one, 

 with which I am acquainted, this species is not affixed by the base to any 

 substance ; it is free. Its dwelling is in deep water, among sand, at the 

 bottom of the sea ; and it is usually recovered by means of the fishermen's 

 lines, but not, as I understand, from touching or seizing the bait. 



Though classing the animal here with the Ascidia, I apprehend that 

 it may be found only in immediate approximation to the genus, instead of 

 being incorporated along with the other species. At the same time, I am 

 ignorant of any of those to which it is allied. Let its name and position 

 be therefore accepted meantime as provisional, if no other naturalist has 

 already assigned it a place. 



The Ascidia villosa extends from four inches to four and a half in 

 length, by about nine lines in its greatest diameter, towards the lower ex- 

 tremity. The anterior extremity consists of two brief abrupt prolonga- 

 tions, or rather prominences, in lieu of the tubular parts of the Ascidia 

 proper; each with its peculiar orifice, which, in a vigorous specimen, is 

 about half an inch beyond the forking of both from the body. The poste- 

 rior extremity of the body may be compared to the transverse half of an 

 ovoid ; it is somewhat villous, and frequently invested with fine sand. 



This animal is round, wholly of reddish-brown colour; the interior of 

 the orifices scarlet. 



Whether the posterior extremity is sunk amidst the sand in its na- 



