CLASSIFICATION OF THE TUNICATA. 611 



Test gelatinous, penetrated by the ectodermal prolongations 

 from the ascidiozooids. 



Branchial sac well developed ; no internal longitudinal bars 

 present. 



Dorsal lamina composed of languets. 



Alimentary canal posterior to the branchial sac. 



Gonads placed on the left side of the intestinal loop. Testes 

 grape-like in arrangement. Embryos develop in an incubatory 

 pouch which is a large diverticulum from the atrial cavity. 



The species of Colella may be distinguished as follows : — 



/ Peduncle branched 1 



\ Peduncle unbranched 2 



r Lower end of peduncle branched 3 



1 \ Upper end of peduncle branched, 3 rows of stigmata, tentacles 5 large 

 [ and 5 small C plicata, n. s^p. (Austr.) 



(Peduncle short and wide, tentacles 16, 8 rows of stigmata. 

 C. concreta, Herdm. (A. Arct.) 

 Peduncle long and narrow 4 



r Tentacles 12, all of one size, 4 rows of stigmata. 

 4 \ C. ramulosa, Herdm. (S. Pac.) 



[ Tentacles of two sizes C. tenuioaulis, n. sp. (Austr.) 



Q f Peduncle longer than body , 5 



I Peduncle not longer than body 6 



(Colour red, tentacles 12 C. pulchra, Herdm. (Austr.) 

 Colour bluish, tentacles 8, many rows of stigmata. 

 C. Thomsvni, Herdm. (Mai.) 

 Colour greyish yellow 7 



r Tentacles large, 16 ; 5 rows of stigmata. [A. Arct. 



7 \ G. fedimculata, Q. & G. (Austr., 



I Tentacles small, 8 C. Gaimardi, Herdm. (S. Atl.) 



n [Colony wide at top 8 



\ Colony narrow at top 9 



of Colour grey C. ilf«rray«, Herdm. (S. Pac.) 



[ Colour with a reddish tinge do., var. ruhida, Herdm. (Austr.) 



f Body not longer than broad, tentacles 12, 4 rows of stigmata. 

 9 \ C. Quoyi, Herdm. (A. Arct.) 

 [ Body longer than broad 10 



{Ascidiozooids less than 2 mm. long, tentacles numerous (16 large and 

 16 small) and close C. eloiigata,'Rei-(\\Q. (Austr.) 

 Aiicidiozooids more than 5 mm. long, tentacles not numerous. 

 C. clavijorviis, n. sp. (Austr.) 



OxTCOETNiA, von DrascJie, 1882. 



Colony club-shaped, pedunculated. The peduncle traversed by 

 the long vascular appendages of the ascidiozooids, from which 

 buds are formed. 



Ascidiozooids completely imbedded in the common test ; divided 

 into thorax and abdomen, and having loug ectodermal appen- 



