OP TUBULAR AND CELLULAR POLYPI, AND OF ASCIDIiE. 385 



ciliated arms, which has hitherto been placed among the Sertularice; where the sub- 

 genus is characterized by the distribution of its cells in groups, at parts of the 

 branches ; and it may serve to show how secondary are characters derived from the 

 mode of growth, in a natural arrangement of zoophytes, that a cell and animal which 

 appear identical with this, are met with as a crust only, on the stalks of fuci. 



Anguinaria angmna, fig. 4, evidently requires to be transferred from the Tubu- 

 larice to the present family ; and also the subgenus Tibiana, or at least the elegant 

 little species, fig. 5, which has the spot of revolution visible, the mottled sac, and the 

 filaments between the animal and the bottom of the cell. 



A zoophyte allied to the above was found upon the same marine plants, which 

 seems to be that imperfectly represented by Ellis, pi. xxxviii. 5. F. 



It consists of a creeping tube and a number of stems branching from it, each end- 

 ing in an animal that is shown (not very distinctly) at fig. 6. The stems, though 

 commonly still, have free power of motion ; and when one is disturbed it bends 

 quickly to and fro, so as to strike one or two more : these again strike upon others, 

 and thus for a few seconds all are in action ; but they soon return to quietness, and 

 the arms, which during the commotion had been doubled in, open again. 



The arms are placed on the edge of a pretty transparent tunic, and have granu- 

 lations on their back. They are fringed with ciliae possessing the same action as 

 those of Ascidioe and Flustroe ; and in the specimen drawn, small substances were 

 occasionally seen carried downwards along them. As in Flustra, a part of the intes- 

 tine had within it a revolution of particles and dark matter round its axis, and this 

 part communicated with an ascending rectum. The arms at the part of the circle 

 opposite to the rectum appeared to be continued below the edge of the tunic, and 

 the current produced in the water and the food it brought flowed into a cavity 

 there, at the bottom of which was active indistinct motion as if of filaments. A con- 

 nexion was thought to exist between that part and the place where the revolution 

 was going on, but no act of deglutition was perceived. 



No current of blood was visible in the stem, nor any circulation either in the body 

 or the arms. Much of the space within the tunic was occupied by a darkish appear- 

 ance, the nature of which, was not ascertained. I had not opportunity to inspect 

 other individuals, but the species seemed to be intermediate between such animals 

 oi Fhistra as I had met with, and the pedunculated compound Ascidia ; more nearly 

 related to the former, but approaching the latter in the form of the lower part of the 

 body, the position of the rectum, and the absence of all apparent effbrt of swallow- 

 ing : and if with the help of imagination we could connect the ciliated arms together 

 by cross bands at intervals and unite their ends in a circle, extending the tunic to 

 meet that circle, and leaving an opening for the funnel where the rectum is placed, 

 the organ would not be unlike the branchiae of some Ascidice, Indeed the affinity 

 appeared to me not very distant between Ascidia and Flustra ; while, to the Sertii- 



