710 



STYELOIDES EVISCERANS. 



budded from a parent stock. There is however, so far as I could ascertain by dissection, 

 no organic union. 



Why one species should act in the way described while another attached perhaps 

 to the same stone does not, is a question not easily answered, but the fact affords 

 a .special case of self-mutilation or autotomy, a phenomenon of wide distribution in the 

 animal kingdom, varying greatly in its manifestations. 



Fig. 10. Group of seven individuals of Styeloides eviscerans, represented as lying attached to the surface 

 of a fragment of stone. In the large individual to the right the digestive tract is indicated in process of 

 extrusion through the atrial aperture, a. Anus with frilled margin, i. Intestine, br. s. Branchial sac. 

 e. Endostyle. h. Foreign organisms attached to test. (From Quart. J. Micr. Set., Vol. 39, 1896.) 



The genus Styeloides was established in 188.5 by Dr Sluiter' for a species found 

 b}' him near Batavia, which appeared to be normally destitute of a branchial sac. 

 Subsequently he returned to the subject and suggested that the branchial sac anfl 

 intestine are lost in the adult jjeriod only'^ 



' Natuurk. Tijdsclir. Nederl. Imh, Bd. 4.5, 188.5, Styeloides abranchiata. Sluiter. 



- Sluiter, C. Ph., "Tunicaten." Semon's Zool. Forschiingsreisen, v. 1895, Styela solvens, p. 182. 



