THE AUSTBALIAN MUSEUM. 



Out of the six genera placed in this family in the Eeport on the 

 " Challenger" Tunicata, only two are represented in the present collec- 

 tion ; one being the " Challenger " genus Ghorizocormus, of which there 

 are three new species, and the other being the genus Goodsiria, to which 

 one species is now added. The following table shows how the genera 

 and species of this family may be briefly distinguished, and indicates the 

 position of the new forms. For a discussion of the history and relations 

 of the members of the family reference must be made to the "Challenger" 

 Eeport.* 



Polystyelidae. 



2 



6 



"{ 



9 



Ascidiozooids projecting above the sur- 

 face of the test ... 



Ascidiozooids completely imbedded in 

 the test ... 



Ascidiozooids with no abdomen (Poly- 

 styela) ... 



With abdomen as long as thorax (Thy- 

 lacium) ... 



It is doubtful whether the two species 

 are really distinct 



Colony formed of small masses united by 

 creeping stolons (Ghorizocormus) 



Colony continuous, not broken up 



Branchial sac having rudimentary folds... 



Branchial sac with no rudimentary folds 



Atrial tentacles more than 20 in number 



Atrial tentacles not more than 20 



16 branchial tentacles, 7 rows of stigmata 



10 branchial tentacles, 10 rows of stigmata 



Colony thick and massive (Goodsiria) ... 



Colony thin and encrusting (Synstyela)... 



Test encrusted with sandf 



Not encrusted with sand ... 



Flesh colour, marked with red ... 



Light grey, with bluish and pink tints ... 



1 

 2 

 P. lemirri, Giard. 



T. sylvani, Car. 

 T. normani, Aid. 



4 



5 

 C. reticidata, Herdm. 



6 

 C. sydneyensis, Herdm. 



7 



C. leucophcBus, Herdm. 

 C. subfuscus, Herdm. 



8 



9 

 G. lapidosa, Herdm. 



10 



S. variegata, Aid. 

 S. incrustans, Herdm. 



* Part II., p. 323 ; and Part III., p. 144. 



+ The genus Oculiiuiria of Gray appears to be related here, but the description (Proc. 

 Zool. Soc. L., 1868, p. 564), is not sufficient to determine the position with certainty 

 see "Challenger" Report, Part II., p. 323, 



