CLASSIFICATION OF THE TUXICATA. 599 



belong to Clona, and may, some of them, be syuonyins of C. intes- 

 tinal is : — 



Jsoidia virescens, Bruguiere. (N.W. Eur.) 



A. cormgata, 0. F. Miiller. (N.W. Eur.) 



A. ocellata, Agassiz. (E. N. Am.) 



A. fenella, fe'timpson. ^E. N. Am.) 



A. pitlckella, Alder. (N.W.Eur.) 



Ali7ia meridionalis, Eisso (Med.), may be a Ciona, or possibly a Clavelinid. 



Eamily lY. CIjkNELmiDM, Forhes, 1S53. 



Body attacbed by tbe posterior end, and usually by means of 

 a peduncle, to a creeping basal stolon or common stolonial mass 

 from which young ascidiozooids are formed by gemmation. 



Test gelatinous, rarely cartilaginous, usually thin and trans- 

 parent. Apertures circular, very rarely distinctly lobed. 



Sninchial sac not folded, often Avitbout internal longitudinal 

 bars. The bars, if present, have no papillae. The stigmata are 

 straight. 



Dorsal lamina represented by languets. 



Tentacles simple, filiform. 



Alimentary canal usually extending beyond the branchial sac 

 posteriorly to form an abdomen. 



Gonads placed in the intestinal loop. In addition to sexual 

 reproduction, colonies may be formed asexually by gemmation 

 from the stolon. 



This family contains 10 genera *, which may be distinguished aa 

 follows : — 



r Branchial sac with internal longitudinal bars 1 



\ Branchial sac without internal longitudinal bars 2 



1 f Body divided into distinct abdomen and thoi'ax 3 



[ No distinct abdomen present 4 



r Many ascidiozooids united by their posterior parts to form a large 



S] colony Diazona. 



[ Few ascidiozooids united irregularly to I'orm small colony 5 



K \ Branchial sac minutely plicated Rhopalsea. 



I Branchial sac not minutely plicated Rhopalopsis. 



, r Blood-vessels in the test Sluiteria. 



[No blood-vessels in the test Ecteinascidia. 



2 J No distinct abdomen present 6 



\ Abdomen distinct from the thorax 7 



„ [Branchial sac with about 4 rows of stigmata Perophora. 



[ With about a dozen rows of stigmata Perophoropsis. 



* Clavelinopsis, Fewkes, probably does not belong to this family. The single 

 species C. rubra seems to be a Boltenia. 



liINN. JOUKN. — ZOOLOay, YOL. XXIII. 43 



