PROF. W. A. HEEDMAN OiST BEITISH TUNICATA. 433 



a. Branchial sac with well-marked papillae. A. venosa, 0. F. M. 

 I. No papillae. 



1. Dorsal lamina witli plain margin .... A. virginea, 0. F. M. 



2. Dorsal lamina witll margin more or less toothed. 



a. Attached by small area, branchial lobes denticulated, 

 about 5 stigmata in mesh A. aspersa, 0. F. M. 



/3. Attached by whole left side, branchial lobes rounded, 

 from 7-12 stigmata in mesh .... A. scahra. 0. F. M. 



I have lately gone over carefully the descriptions and figures of 

 Ascidians given by 0. F. Miiller in the ' Zoologia Danica ; ' and 

 I believe it will be useful if I give here a list of his 20 species, 

 putting opposite each what is now considered the proper name 

 according to my judgment. It will be noticed that his 20 

 species of Ascidia become reduced to about 16 species, referable 

 to 9 different genera and 4 families. Nearly all these forms are 

 British. 



List of Ascidians in 0. F. Miiller s 'Zoologia Danica.' 

 Ascidia. 

 A. mentula =Ascidia mentula, 0. F. M. 



A. rustica =Styela rustica (L.). 



A. venosa =? present Ascidiella venosa-, or ? red soft 



variety of A. mentula. 

 A. prunum =? Ascidiella scahra (0. F. M.). 



A. concMlega ===? Ascidia pleheia; ? Polycarpa comata\ or 



? not British *. 

 A. parallelogramona^^Corella parallelogramma (0. F. M.). 

 A. virginea =Ascidiella virginea (0. F. M.). 



A. canina =^Ciona canina (0. F. M.), a var. of C. intes- 



tinalis (L.) [figs. 1-S=C. intestinalisl. 

 A. patula =^? Ascidiella aspersa (0. F. M.) ; or ? not 



British. 

 A. aspersa ^Ascidiella aspersa (0. F. M.). 



A. scabra —Ascidiella scahra (0. F. M.). 



A. orhicularis = ? Ascidiella scahra ; or ? not British. 



A. corrugata = Ciona intestinalis (L.). 



A. lepadiformis =Clavelina lepadiformis (0. F. M.). 



* It was re-described by Kiipffer in 1875 as a Thallusia from Norwegian 

 specimens, but is apparently not known to Traustedt. 



