CLASSIFICATION OF THE TUNICATA. 637 



Stnsttela, Giard, 187Ji. 



Colony thin and incrusting. 



Ascidiozooids large and closely placed, completely imbedded in 

 the common test. Body not divided into thorax and abdomen. 



Test relatively small in amount. Matrix sometimes fibrillated ; 

 test-cells small ; bladder-cells absent ; vessels present. 



Sranchial sac well developed. Rudimentary folds present. 

 Internal longitudinal bars well marked. 



Dorsal lamina in the form of a plain membrane. 



Tentacles well developed. 



Alimentary canal not prolonged behind the branchial sac. 

 Stomach folded longitudinally. 



Gonads in the form of polycarps attached to the mantle. 



Two species of Synstyela are known : — 



r Flesh -colour, marked with red S. variegata*. Aid. (N.W. Eur.) 



\ Light grey, with bluish and pink tints. [Mai.) 



[ 8. incrustans, Herdm. (Mag. & 



GoODsiEiA, Cunningliam, 1871. 



Colony massive, sessile or pedunculated, not incrusted with 

 sand. 



Ascidiozooids large and ovate in shape, completely imbedded 

 in the common test; not divided into thorax and abdomen. 

 Apertures 4-lobed, both on the anterior end. 



Test solid, cartilaginous, not sandy. Matrix delicately fibril- 

 lated. Vessels present. 



Brancliial sac well developed ; folds present, rudimentary, or 

 absent ; internal longitudinal bars always present. 



Dorsal lamina in the form of a plain membrane. 



Alimentary canal not prolonged behind the branchial sac. 

 Stomach folded longitudinally. 



Gonads in the form of polycarps. 



The species of Goodsiria may be distinguished thus : — 



{Test somewhat sandy ; ascidiozooids elongated. 

 G. lapidosa, n. sp. (Austr.) 

 Test not sandy ; ascidiozooids rounded 1 



* Possibly G-iard's Synstyela from the French coast m?y be distinct from this 

 British species. 



