REPORT ON THE TUNIC AT A. 37 



DoLiOLiD.E. It is clearly distinguished from the second suborder, the Hemimyariu, by 

 the condition of the muscle bands and of the branchial sac, and by the life-history. 

 The muscle bands are complete rings, while in the Hemimyaria they are always more 

 or less incomplete. The branchial sac in the Cyclomyaria has always a distinct cavity, 

 and communicates with the peribranchial cavity only by small slits or stigmata. The 

 life-history is also very characteristic, as the sexual generation in the Cyclomyaria is 

 always polymorphous, while in the Hemimyaria it consists of one form only. 



Family Doliolid.e. 



Body free, more or less barrel-shaped ; branchial and atrial apertures terminal, 



lobed. 

 Test rather slightly developed. 

 Mantle containing transverse muscle bands, which form hoops surrounding the 



body. 

 Branchial Sac well developed. Stigmata not numerous, generally placed far 



back. 

 Dorsal Lamina and Tentacles absent. 



Alimentary Canal at the posterior end of the branchial sac. 

 Bejjroductivc Organs hermaphrodite.. 

 Gemmation takes place. 

 Life-History complicated by alternation of generations and polymorphism. 



This family contains two genera : Doliolum, Quoy and Gaimard, and Anchinia, 

 Eschscholtz (and later, C. Vogt). It was first formed as a family by Keferstein ^ in 

 1862, and since then it has always been placed in its present position along with the 

 Salpidae in the group Thaliacea. 



The genus Doliolum is well represented in the Challenger collection, but no speci- 

 mens referable to the genus Anchinia were obtained. 



o^ 



Genus Doliolum, Quoy and Gaimard. 



Body always more or less barrel-shaped, not attached, and never forming a 

 colony. Branchial aperture at the anterior end, atrial at the posterior, both 

 surrounded by lobes. 



Test very thin, containing no test cells. 



Mantle containing well-developed, transversely-arranged muscle bands, which in 

 the fully-developed sexual animal are always eight in number. They sur- 

 round the body like hoops. 



' Bronn's Klass. u. Ord. d. Thierreichs, Bd. iii. p. 216. 



